{"transactions":[{"id":688504,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2026-08-13T20:30:07.000Z","date":"2026-08-11","kind":"exercise","planned":false,"acquired":true,"shares":5000000,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 8,187,302 shares of Series B Common Stock held by Fund IX-A, (ii) 5,112,037 shares of Series B Common Stock held by Fund IX-B, (iii) 504,825 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 43,030 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 5,584 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":13852778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":5000000},"source":{"system":"sec-edgar","filing":"0001193125-26-349311","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000119312526349311/ownership.xml","form_type":"4"}},{"id":688503,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2026-08-13T20:30:07.000Z","date":"2026-08-11","kind":"sale","planned":false,"acquired":false,"shares":5000000,"price":17.71,"value":88550000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001193125-26-349311","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000119312526349311/ownership.xml","form_type":"4"}},{"id":688502,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2026-08-13T20:30:07.000Z","date":"2026-08-11","kind":"exercise","planned":false,"acquired":true,"shares":5000000,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":5000000,"source":{"system":"sec-edgar","filing":"0001193125-26-349311","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000119312526349311/ownership.xml","form_type":"4"}},{"id":1044403,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2025-09-10T20:15:16.000Z","date":"2025-09-08","kind":"exercise","planned":false,"acquired":true,"shares":4000000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 11,142,414 shares of Series B Common Stock held by Fund IX-A, (ii) 6,957,168 shares of Series B Common Stock held by Fund IX-B, (iii) 687,035 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 58,561 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 7,600 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":18852778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":4000000},"source":{"system":"sec-edgar","filing":"0000950170-25-113988","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025113988/ownership.xml","form_type":"4"}},{"id":1044402,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-09-10T20:15:16.000Z","date":"2025-09-08","kind":"sale","planned":false,"acquired":false,"shares":4000000,"price":31.87,"value":127480000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-25-113988","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025113988/ownership.xml","form_type":"4"}},{"id":1044401,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-09-10T20:15:16.000Z","date":"2025-09-08","kind":"exercise","planned":false,"acquired":true,"shares":4000000,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":4000000,"source":{"system":"sec-edgar","filing":"0000950170-25-113988","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025113988/ownership.xml","form_type":"4"}},{"id":1055000,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2025-08-27T20:05:07.000Z","date":"2025-08-25","kind":"exercise","planned":false,"acquired":true,"shares":975000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 13,506,504 shares of Series B Common Stock held by Fund IX-A, (ii) 8,433,272 shares of Series B Common Stock held by Fund IX-B, (iii) 832,803 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 70,986 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 9,213 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":22852778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":975000},"source":{"system":"sec-edgar","filing":"0001415889-25-023115","document":"form4-08272025_080802.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588925023115/form4-08272025_080802.xml","form_type":"4"}},{"id":1054999,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-08-27T20:05:07.000Z","date":"2025-08-25","kind":"sale","planned":false,"acquired":false,"shares":975000,"price":30.01,"value":29259750.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-25-023115","document":"form4-08272025_080802.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588925023115/form4-08272025_080802.xml","form_type":"4"}},{"id":1054998,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-08-27T20:05:07.000Z","date":"2025-08-25","kind":"exercise","planned":false,"acquired":true,"shares":975000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":975000,"source":{"system":"sec-edgar","filing":"0001415889-25-023115","document":"form4-08272025_080802.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588925023115/form4-08272025_080802.xml","form_type":"4"}},{"id":1058772,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-08-22T20:12:34.000Z","date":"2025-08-21","kind":"other","planned":false,"acquired":false,"shares":500000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents a distribution of 307,809 shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\") held by Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and 192,191 shares of Series A Common Stock held by Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"), in each case to facilitate bona fide charitable gifts."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Fund IX-A and Fund IX-B. The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-25-110957","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025110957/ownership.xml","form_type":"4"}},{"id":1060841,"issuer":{"id":3936,"kind":"organization","name":"LifeStance Health Group, Inc.","symbol":"LFST"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":false,"other":true,"other_text":"shareholder"}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":false,"other":true,"other_text":"shareholder"}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":4,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":false,"other":true,"other_text":"owner"}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":5,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":false,"other":true,"other_text":"Owner"}},{"id":76312,"kind":"organization","name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","position":6,"cik":"0001660981","reported_name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":false,"other":true,"other_text":"Owner"}}],"security":"Common Stock","published_at":"2025-08-20T20:34:29.000Z","date":"2025-08-18","kind":"sale","planned":false,"acquired":false,"shares":8407643,"price":5.07,"value":42626750.01,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents 5,148,494 shares sold by Summit Partners Growth Equity Fund IX-A, L.P., 3,214,648 shares sold by Summit Partners Growth Equity Fund IX-B, L.P., 35,938 shares sold by Summit Investors GE IX/VC IV, LLC, 4,804 shares sold by Summit Partners Entrepreneur Advisors Fund II, L.P. and 3,759 shares sold by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"The reported securities are held as follows: 20,529,149 shares in the name of Summit Partners Growth Equity Fund IX-A, L.P.; 12,818,117 shares in the name of Summit Partners Growth Equity Fund IX-B, L.P.; 143,301 shares in the name of Summit Investors GE IX/VC IV, LLC; 19,157 shares in the name of Summit Partners Entrepreneur Advisors Fund II, L.P.; and 14,991 shares in the name of Summit Investors GE IX/ VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F3","text":"Summit Partners, L.P. is the managing member of Summit Partners GE IX, LLC, which is general partner of Summit Partners GE IX, L.P., which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. and Summit Partners Growth Equity Fund IX-B, L.P. Summit Master Company, LLC is (i) the sole member of Summit Partners Entrepreneur Advisors GP II, LLC, which is the general partner of Summit Partners Entrepreneur Advisors Fund II, L.P. and (ii) the general partner of Summit Partners L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC, and the general partner of Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F4","text":"Summit Master Company, LLC, as the sole member of Summit Partners Entrepreneur Advisors GP II, LLC and the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to LifeStance Health Group, Inc. Summit Partners, L.P., through a four-person investment committee, currently composed of Peter Y. Chung, Mark A. deLaar, Darren M. Black and Craig D. Frances, has voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Each of the Summit Funds, Mr. Chung, Mr. deLaar, Mr. Black and Dr. Frances disclaim beneficial ownership of the shares, except, in each case, to the extent of such person's or entity's pecuniary interest therein."}],"balance_after":33524715,"source":{"system":"sec-edgar","filing":"0001415889-25-022457","document":"form4-08202025_080825.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588925022457/form4-08202025_080825.xml","form_type":"4"}},{"id":1065927,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2025-08-15T20:17:27.000Z","date":"2025-08-13","kind":"exercise","planned":false,"acquired":true,"shares":7000000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Consists of (i) 14,082,751  shares of Series B Common Stock held by Fund IX-A, (ii) 8,793,072 shares of Series B Common Stock held by Fund IX-B, (iii) 868,334 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 74,015 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 9,606 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":23827778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":7000000},"source":{"system":"sec-edgar","filing":"0000950170-25-109399","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025109399/ownership.xml","form_type":"4"}},{"id":1065926,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-08-15T20:17:27.000Z","date":"2025-08-13","kind":"sale","planned":false,"acquired":false,"shares":6500000,"price":30.01,"value":195065000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 307,809 shares of Series A Common Stock held by Fund IX-A and (ii) 192,191 shares of Series A Common Stock held by Fund IX-B, in each case to facilitate charitable giving."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":500000,"source":{"system":"sec-edgar","filing":"0000950170-25-109399","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025109399/ownership.xml","form_type":"4"}},{"id":1065925,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-08-15T20:17:27.000Z","date":"2025-08-13","kind":"exercise","planned":false,"acquired":true,"shares":7000000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":7000000,"source":{"system":"sec-edgar","filing":"0000950170-25-109399","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025109399/ownership.xml","form_type":"4"}},{"id":1122097,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2025-06-05T23:13:36.000Z","date":"2025-06-04","kind":"exercise","planned":false,"acquired":true,"shares":4000000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 18,219,907 shares of Series B Common Stock held by Fund IX-A, (ii) 11,376,255 shares of Series B Common Stock held by Fund IX-B, (iii) 1,123,429  shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 95,759 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 12,428 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":30827778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":4000000},"source":{"system":"sec-edgar","filing":"0000950170-25-082604","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025082604/ownership.xml","form_type":"4"}},{"id":1122096,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-06-05T23:13:36.000Z","date":"2025-06-04","kind":"sale","planned":false,"acquired":false,"shares":4000000,"price":33.35,"value":133400000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-25-082604","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025082604/ownership.xml","form_type":"4"}},{"id":1122095,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-06-05T23:13:36.000Z","date":"2025-06-04","kind":"exercise","planned":false,"acquired":true,"shares":4000000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":4000000,"source":{"system":"sec-edgar","filing":"0000950170-25-082604","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025082604/ownership.xml","form_type":"4"}},{"id":1141257,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2025-05-20T22:25:33.000Z","date":"2025-05-19","kind":"exercise","planned":false,"acquired":true,"shares":4000000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 20,583,996 shares of Series B Common Stock held by Fund IX-A, (ii) 12,852,359 shares of Series B Common Stock held by Fund IX-B, (iii) 1,269,198  shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 108,184 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 14,041 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":34827778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":4000000},"source":{"system":"sec-edgar","filing":"0000950170-25-075445","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025075445/ownership.xml","form_type":"4"}},{"id":1141256,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-05-20T22:25:33.000Z","date":"2025-05-19","kind":"sale","planned":false,"acquired":false,"shares":4000000,"price":33,"value":132000000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-25-075445","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025075445/ownership.xml","form_type":"4"}},{"id":1141255,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-05-20T22:25:33.000Z","date":"2025-05-19","kind":"exercise","planned":false,"acquired":true,"shares":4000000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":4000000,"source":{"system":"sec-edgar","filing":"0000950170-25-075445","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025075445/ownership.xml","form_type":"4"}},{"id":1205013,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2025-03-17T21:11:38.000Z","date":"2025-03-14","kind":"exercise","planned":false,"acquired":true,"shares":2000000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 22,948,085 shares of Series B Common Stock held by Fund IX-A, (ii) 14,328,463 shares of Series B Common Stock held by Fund IX-B, (iii) 1,414,967 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 120,609 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 15,654 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":38827778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":2000000},"source":{"system":"sec-edgar","filing":"0000950170-25-040470","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025040470/ownership.xml","form_type":"4"}},{"id":1205012,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-03-17T21:11:38.000Z","date":"2025-03-14","kind":"sale","planned":false,"acquired":false,"shares":2000000,"price":32.44,"value":64880000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-25-040470","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025040470/ownership.xml","form_type":"4"}},{"id":1205011,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2025-03-17T21:11:38.000Z","date":"2025-03-14","kind":"exercise","planned":false,"acquired":true,"shares":2000000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":2000000,"source":{"system":"sec-edgar","filing":"0000950170-25-040470","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017025040470/ownership.xml","form_type":"4"}},{"id":1336399,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-12-11T21:57:39.000Z","date":"2024-12-09","kind":"exercise","planned":false,"acquired":true,"shares":2100000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On December 9, 2024, the reporting persons directed the sale of an aggregate of 2,100,000 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On December 9, 2024, the reporting persons directed the sale of an aggregate of 2,100,000 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On December 9, 2024, the reporting persons directed the sale of an aggregate of 2,100,000 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 24,130,130 shares of Series B Common Stock held by Fund IX-A, (ii) 15,066,515 shares of Series B Common Stock held by Fund IX-B, (iii) 1,487,851 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 126,822 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 16,460 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":40827778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":2100000},"source":{"system":"sec-edgar","filing":"0000950170-24-135422","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024135422/ownership.xml","form_type":"4"}},{"id":1336398,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-12-11T21:57:39.000Z","date":"2024-12-09","kind":"sale","planned":false,"acquired":false,"shares":2100000,"price":39.15,"value":82215000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-24-135422","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024135422/ownership.xml","form_type":"4"}},{"id":1336397,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-12-11T21:57:39.000Z","date":"2024-12-09","kind":"exercise","planned":false,"acquired":true,"shares":2100000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On December 9, 2024, the reporting persons directed the sale of an aggregate of 2,100,000 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":2100000,"source":{"system":"sec-edgar","filing":"0000950170-24-135422","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024135422/ownership.xml","form_type":"4"}},{"id":1353387,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-11-25T21:05:15.000Z","date":"2024-11-25","kind":"other","planned":false,"acquired":false,"shares":346707,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents a distribution of 213,439 shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\") held by Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and 133,268 shares of Series A Common Stock held by Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"), in each case to facilitate bona fide charitable gifts."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Fund IX-A and Fund IX-B. The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000950170-24-130550","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024130550/ownership.xml","form_type":"4"}},{"id":1362738,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-11-18T21:25:17.000Z","date":"2024-11-14","kind":"exercise","planned":false,"acquired":true,"shares":3500000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Consists of (i) 25,371,277 shares of Series B Common Stock held by Fund IX-A, (ii) 15,841,470 shares of Series B Common Stock held by Fund IX-B, (iii) 1,564,379 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 133,345 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 17,307 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 3) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":42927778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":3500000},"source":{"system":"sec-edgar","filing":"0000950170-24-127985","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024127985/ownership.xml","form_type":"4"}},{"id":1362737,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-11-18T21:25:17.000Z","date":"2024-11-14","kind":"sale","planned":false,"acquired":false,"shares":3153293,"price":36.2,"value":114149206.6,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 213,439 shares of Series A Common Stock held by Fund IX-A and (ii) 133,268 shares of Series A Common Stock held by Fund IX-B."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 3) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":346707,"source":{"system":"sec-edgar","filing":"0000950170-24-127985","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024127985/ownership.xml","form_type":"4"}},{"id":1362736,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-11-18T21:25:17.000Z","date":"2024-11-14","kind":"exercise","planned":false,"acquired":true,"shares":3500000,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 3) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the securities held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":3500000,"source":{"system":"sec-edgar","filing":"0000950170-24-127985","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000095017024127985/ownership.xml","form_type":"4"}},{"id":1406049,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-09-17T20:23:31.000Z","date":"2024-09-13","kind":"exercise","planned":false,"acquired":true,"shares":113561,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 13, 2024, the reporting persons directed the sale of an aggregate of 113,561 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 13, 2024, the reporting persons directed the sale of an aggregate of 113,561 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 13, 2024, the reporting persons directed the sale of an aggregate of 113,561 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,439,856 shares of Series B Common Stock held by Fund IX-A, (ii) 17,133,061 shares of Series B Common Stock held by Fund IX-B, (iii) 1,691,926 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,217 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,718 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46427778,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":113561},"source":{"system":"sec-edgar","filing":"0001415889-24-023518","document":"form4-09172024_080927.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023518/form4-09172024_080927.xml","form_type":"4"}},{"id":1406048,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-17T20:23:31.000Z","date":"2024-09-13","kind":"sale","planned":false,"acquired":false,"shares":113561,"price":31.47,"value":3573764.67,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-023518","document":"form4-09172024_080927.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023518/form4-09172024_080927.xml","form_type":"4"}},{"id":1406047,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-17T20:23:31.000Z","date":"2024-09-13","kind":"exercise","planned":false,"acquired":true,"shares":113561,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 13, 2024, the reporting persons directed the sale of an aggregate of 113,561 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":113561,"source":{"system":"sec-edgar","filing":"0001415889-24-023518","document":"form4-09172024_080927.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023518/form4-09172024_080927.xml","form_type":"4"}},{"id":1407193,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-09-16T21:05:45.000Z","date":"2024-09-12","kind":"exercise","planned":false,"acquired":true,"shares":107205,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 12, 2024, the reporting persons directed the sale of an aggregate of 107,205 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 12, 2024, the reporting persons directed the sale of an aggregate of 107,205 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 12, 2024, the reporting persons directed the sale of an aggregate of 107,205 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,506,973 shares of Series B Common Stock held by Fund IX-A, (ii) 17,174,968 shares of Series B Common Stock held by Fund IX-B, (iii) 1,696,064 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,570 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,764 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46541339,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":107205},"source":{"system":"sec-edgar","filing":"0001415889-24-023447","document":"form4-09162024_090941.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023447/form4-09162024_090941.xml","form_type":"4"}},{"id":1407192,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-16T21:05:45.000Z","date":"2024-09-12","kind":"sale","planned":false,"acquired":false,"shares":107205,"price":31.33,"value":3358732.65,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-023447","document":"form4-09162024_090941.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023447/form4-09162024_090941.xml","form_type":"4"}},{"id":1407191,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-16T21:05:45.000Z","date":"2024-09-12","kind":"exercise","planned":false,"acquired":true,"shares":107205,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 12, 2024, the reporting persons directed the sale of an aggregate of 107,205 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":107205,"source":{"system":"sec-edgar","filing":"0001415889-24-023447","document":"form4-09162024_090941.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023447/form4-09162024_090941.xml","form_type":"4"}},{"id":1408113,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-09-13T20:01:24.000Z","date":"2024-09-11","kind":"exercise","planned":false,"acquired":true,"shares":2942,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 11, 2024, the reporting persons directed the sale of an aggregate of 2,942 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 11, 2024, the reporting persons directed the sale of an aggregate of 2,942 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 11, 2024, the reporting persons directed the sale of an aggregate of 2,942 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,570,334 shares of Series B Common Stock held by Fund IX-A, (ii) 17,214,529 shares of Series B Common Stock held by Fund IX-B, (iii) 1,699,971 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,903 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,807 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46648544,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":2942},"source":{"system":"sec-edgar","filing":"0001415889-24-023354","document":"form4-09132024_080920.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023354/form4-09132024_080920.xml","form_type":"4"}},{"id":1408112,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-13T20:01:24.000Z","date":"2024-09-11","kind":"sale","planned":false,"acquired":false,"shares":2942,"price":31.01,"value":91231.42,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-023354","document":"form4-09132024_080920.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023354/form4-09132024_080920.xml","form_type":"4"}},{"id":1408111,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-13T20:01:24.000Z","date":"2024-09-11","kind":"exercise","planned":false,"acquired":true,"shares":2942,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 11, 2024, the reporting persons directed the sale of an aggregate of 2,942 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":2942,"source":{"system":"sec-edgar","filing":"0001415889-24-023354","document":"form4-09132024_080920.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924023354/form4-09132024_080920.xml","form_type":"4"}},{"id":1414755,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-09-05T20:00:39.000Z","date":"2024-09-03","kind":"exercise","planned":false,"acquired":true,"shares":6039,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 3, 2024, the reporting persons directed the sale of an aggregate of 6,039 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 3, 2024, the reporting persons directed the sale of an aggregate of 6,039 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 3, 2024, the reporting persons directed the sale of an aggregate of 6,039 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,572,073 shares of Series B Common Stock held by Fund IX-A, (ii) 17,215,614 shares of Series B Common Stock held by Fund IX-B, (iii) 1,700,078 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,912 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,809 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46651486,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":6039},"source":{"system":"sec-edgar","filing":"0001415889-24-022891","document":"form4-09052024_080933.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022891/form4-09052024_080933.xml","form_type":"4"}},{"id":1414754,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-05T20:00:39.000Z","date":"2024-09-03","kind":"sale","planned":false,"acquired":false,"shares":6039,"price":31.53,"value":190409.67,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022891","document":"form4-09052024_080933.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022891/form4-09052024_080933.xml","form_type":"4"}},{"id":1414753,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-05T20:00:39.000Z","date":"2024-09-03","kind":"exercise","planned":false,"acquired":true,"shares":6039,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 3, 2024, the reporting persons directed the sale of an aggregate of 6,039 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":6039,"source":{"system":"sec-edgar","filing":"0001415889-24-022891","document":"form4-09052024_080933.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022891/form4-09052024_080933.xml","form_type":"4"}},{"id":1416888,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-09-04T21:40:45.000Z","date":"2024-08-30","kind":"exercise","planned":false,"acquired":true,"shares":1300,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 30, 2024, the reporting persons directed the sale of an aggregate of 1,300 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 30, 2024, the reporting persons directed the sale of an aggregate of 1,300 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 30, 2024, the reporting persons directed the sale of an aggregate of 1,300 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,575,642 shares of Series B Common Stock held by Fund IX-A, (ii) 17,217,843 shares of Series B Common Stock held by Fund IX-B, (iii) 1,700,298 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,931 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,811 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46657525,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":1300},"source":{"system":"sec-edgar","filing":"0001415889-24-022793","document":"form4-09042024_080932.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022793/form4-09042024_080932.xml","form_type":"4"}},{"id":1416887,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-04T21:40:45.000Z","date":"2024-08-30","kind":"sale","planned":false,"acquired":false,"shares":1300,"price":31.64,"value":41132.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022793","document":"form4-09042024_080932.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022793/form4-09042024_080932.xml","form_type":"4"}},{"id":1416886,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-04T21:40:45.000Z","date":"2024-08-30","kind":"exercise","planned":false,"acquired":true,"shares":1300,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 30, 2024, the reporting persons directed the sale of an aggregate of 1,300 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":1300,"source":{"system":"sec-edgar","filing":"0001415889-24-022793","document":"form4-09042024_080932.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022793/form4-09042024_080932.xml","form_type":"4"}},{"id":1418470,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-09-03T20:20:55.000Z","date":"2024-08-29","kind":"exercise","planned":false,"acquired":true,"shares":16931,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 29, 2024, the reporting persons directed the sale of an aggregate of 16,931 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 29, 2024, the reporting persons directed the sale of an aggregate of 16,931 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 29, 2024, the reporting persons directed the sale of an aggregate of 16,931 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,576,410 shares of Series B common stock held by Fund IX-A, (ii) 17,218,323 shares of Series B Common Stock held by Fund IX-B, (iii) 1,700,345 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,935 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,812 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46658825,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":16931},"source":{"system":"sec-edgar","filing":"0001415889-24-022689","document":"form4-09032024_080950.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022689/form4-09032024_080950.xml","form_type":"4"}},{"id":1418469,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-03T20:20:55.000Z","date":"2024-08-29","kind":"sale","planned":false,"acquired":false,"shares":16931,"price":31.55,"value":534173.05,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022689","document":"form4-09032024_080950.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022689/form4-09032024_080950.xml","form_type":"4"}},{"id":1418468,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-09-03T20:20:55.000Z","date":"2024-08-29","kind":"exercise","planned":false,"acquired":true,"shares":16931,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 29, 2024, the reporting persons directed the sale of an aggregate of 16,931 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":16931,"source":{"system":"sec-edgar","filing":"0001415889-24-022689","document":"form4-09032024_080950.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022689/form4-09032024_080950.xml","form_type":"4"}},{"id":1419422,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-30T20:01:13.000Z","date":"2024-08-28","kind":"exercise","planned":false,"acquired":true,"shares":27445,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 28, 2024, the reporting persons directed the sale of an aggregate of 27,445 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 28, 2024, the reporting persons directed the sale of an aggregate of 27,445 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 28, 2024, the reporting persons directed the sale of an aggregate of 27,445 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,586,416 shares of Series B common stock held by Fund IX-A, (ii) 17,224,571 shares of Series B Common Stock held by Fund IX-B, (iii) 1,700,962 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 144,988 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,819 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46675756,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":27445},"source":{"system":"sec-edgar","filing":"0001415889-24-022618","document":"form4-08302024_080808.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022618/form4-08302024_080808.xml","form_type":"4"}},{"id":1419421,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-30T20:01:13.000Z","date":"2024-08-28","kind":"sale","planned":false,"acquired":false,"shares":27445,"price":31.68,"value":869457.6,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022618","document":"form4-08302024_080808.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022618/form4-08302024_080808.xml","form_type":"4"}},{"id":1419420,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-30T20:01:13.000Z","date":"2024-08-28","kind":"exercise","planned":false,"acquired":true,"shares":27445,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 28, 2024, the reporting persons directed the sale of an aggregate of 27,445 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":27445,"source":{"system":"sec-edgar","filing":"0001415889-24-022618","document":"form4-08302024_080808.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022618/form4-08302024_080808.xml","form_type":"4"}},{"id":1420374,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-29T20:03:21.000Z","date":"2024-08-27","kind":"exercise","planned":false,"acquired":true,"shares":67436,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 27, 2024, the reporting persons directed the sale of an aggregate of 67,436 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 27, 2024, the reporting persons directed the sale of an aggregate of 67,436 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 27, 2024, the reporting persons directed the sale of an aggregate of 67,436 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,602,637 shares of Series B common stock held by Fund IX-A, (ii) 17,234,699 shares of Series B Common Stock held by Fund IX-B, (iii) 1,701,962 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 145,073 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,830 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46703201,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":67436},"source":{"system":"sec-edgar","filing":"0001415889-24-022531","document":"form4-08292024_080816.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022531/form4-08292024_080816.xml","form_type":"4"}},{"id":1420373,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-29T20:03:21.000Z","date":"2024-08-27","kind":"sale","planned":false,"acquired":false,"shares":67436,"price":32.29,"value":2177508.44,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022531","document":"form4-08292024_080816.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022531/form4-08292024_080816.xml","form_type":"4"}},{"id":1420372,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-29T20:03:21.000Z","date":"2024-08-27","kind":"exercise","planned":false,"acquired":true,"shares":67436,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 27, 2024, the reporting persons directed the sale of an aggregate of 67,436 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":67436,"source":{"system":"sec-edgar","filing":"0001415889-24-022531","document":"form4-08292024_080816.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022531/form4-08292024_080816.xml","form_type":"4"}},{"id":1421264,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-28T20:13:07.000Z","date":"2024-08-26","kind":"exercise","planned":false,"acquired":true,"shares":90502,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 26, 2024, the reporting persons directed the sale of an aggregate of 90,502 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 26, 2024, the reporting persons directed the sale of an aggregate of 90,502 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 26, 2024, the reporting persons directed the sale of an aggregate of 90,502 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,642,493 shares of Series B common stock held by Fund IX-A, (ii) 17,259,585 shares of Series B Common Stock held by Fund IX-B, (iii) 1,704,420 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 145,282 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,857 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46770637,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":90502},"source":{"system":"sec-edgar","filing":"0001415889-24-022420","document":"form4-08282024_080802.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022420/form4-08282024_080802.xml","form_type":"4"}},{"id":1421263,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-28T20:13:07.000Z","date":"2024-08-26","kind":"sale","planned":false,"acquired":false,"shares":90502,"price":32.27,"value":2920499.54,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022420","document":"form4-08282024_080802.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022420/form4-08282024_080802.xml","form_type":"4"}},{"id":1421262,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-28T20:13:07.000Z","date":"2024-08-26","kind":"exercise","planned":false,"acquired":true,"shares":90502,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 26, 2024, the reporting persons directed the sale of an aggregate of 90,502 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":90502,"source":{"system":"sec-edgar","filing":"0001415889-24-022420","document":"form4-08282024_080802.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022420/form4-08282024_080802.xml","form_type":"4"}},{"id":1422616,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-27T20:02:51.000Z","date":"2024-08-23","kind":"exercise","planned":false,"acquired":true,"shares":305638,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 23, 2024, the reporting persons directed the sale of an aggregate of 305,638 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 23, 2024, the reporting persons directed the sale of an aggregate of 305,638 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 23, 2024, the reporting persons directed the sale of an aggregate of 305,638 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,695,982 shares of Series B common stock held by Fund IX-A, (ii) 17,292,983 shares of Series B Common Stock held by Fund IX-B, (iii)1,707,718 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 145,563 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 18,893 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":46861139,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":305638},"source":{"system":"sec-edgar","filing":"0001415889-24-022290","document":"form4-08272024_080846.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022290/form4-08272024_080846.xml","form_type":"4"}},{"id":1422615,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-27T20:02:51.000Z","date":"2024-08-23","kind":"sale","planned":false,"acquired":false,"shares":305638,"price":32.33,"value":9881276.54,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022290","document":"form4-08272024_080846.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022290/form4-08272024_080846.xml","form_type":"4"}},{"id":1422614,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-27T20:02:51.000Z","date":"2024-08-23","kind":"exercise","planned":false,"acquired":true,"shares":305638,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 23, 2024, the reporting persons directed the sale of an aggregate of 305,638 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":305638,"source":{"system":"sec-edgar","filing":"0001415889-24-022290","document":"form4-08272024_080846.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022290/form4-08272024_080846.xml","form_type":"4"}},{"id":1423731,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-26T21:16:41.000Z","date":"2024-08-22","kind":"exercise","planned":false,"acquired":true,"shares":82499,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 22, 2024, the reporting persons directed the sale of an aggregate of 82,499 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 22, 2024, the reporting persons directed the sale of an aggregate of 82,499 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 22, 2024, the reporting persons directed the sale of an aggregate of 82,499 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,876,621 shares of Series B common stock held by Fund IX-A, (ii) 17,405,772 shares of Series B Common Stock held by Fund IX-B, (iii) 1,718,856 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 146,512 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 19,016 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":47166777,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":82499},"source":{"system":"sec-edgar","filing":"0001415889-24-022239","document":"form4-08262024_090837.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022239/form4-08262024_090837.xml","form_type":"4"}},{"id":1423730,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-26T21:16:41.000Z","date":"2024-08-22","kind":"sale","planned":false,"acquired":false,"shares":82499,"price":31.76,"value":2620168.24,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022239","document":"form4-08262024_090837.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022239/form4-08262024_090837.xml","form_type":"4"}},{"id":1423729,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-26T21:16:41.000Z","date":"2024-08-22","kind":"exercise","planned":false,"acquired":true,"shares":82499,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 22, 2024, the reporting persons directed the sale of an aggregate of 82,499 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":82499,"source":{"system":"sec-edgar","filing":"0001415889-24-022239","document":"form4-08262024_090837.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022239/form4-08262024_090837.xml","form_type":"4"}},{"id":1424675,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-23T20:02:21.000Z","date":"2024-08-21","kind":"exercise","planned":false,"acquired":true,"shares":113850,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 21, 2024, the reporting persons directed the sale of an aggregate of 113,850 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 21, 2024, the reporting persons directed the sale of an aggregate of 113,850 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 21, 2024, the reporting persons directed the sale of an aggregate of 113,850 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,925,380 shares of Series B common stock held by Fund IX-A, (ii) 17,436,216 shares of Series B Common Stock held by Fund IX-B, (iii) 1,721,863 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 146,768 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 19,049 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":47249276,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":113850},"source":{"system":"sec-edgar","filing":"0001415889-24-022120","document":"form4-08232024_080817.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022120/form4-08232024_080817.xml","form_type":"4"}},{"id":1424674,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-23T20:02:21.000Z","date":"2024-08-21","kind":"sale","planned":false,"acquired":false,"shares":113850,"price":31.76,"value":3615876.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-022120","document":"form4-08232024_080817.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022120/form4-08232024_080817.xml","form_type":"4"}},{"id":1424673,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-23T20:02:21.000Z","date":"2024-08-21","kind":"exercise","planned":false,"acquired":true,"shares":113850,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 21, 2024, the reporting persons directed the sale of an aggregate of 113,850 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":113850,"source":{"system":"sec-edgar","filing":"0001415889-24-022120","document":"form4-08232024_080817.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924022120/form4-08232024_080817.xml","form_type":"4"}},{"id":1426029,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-22T20:06:01.000Z","date":"2024-08-20","kind":"exercise","planned":false,"acquired":true,"shares":135902,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 20, 2024, the reporting persons directed the sale of an aggregate of 135,902 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 20, 2024, the reporting persons directed the sale of an aggregate of 135,902 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 20, 2024, the reporting persons directed the sale of an aggregate of 135,902 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 27,992,668 shares of Series B common stock held by Fund IX-A, (ii) 17,478,229 shares of Series B Common Stock held by Fund IX-B, (iii) 1,726,012 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 147,122 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 19,095 shares of Series B Common Stock held by Fund IX/VC IV (UK)"},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":47363126,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":135902},"source":{"system":"sec-edgar","filing":"0001415889-24-021998","document":"form4-08222024_080855.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924021998/form4-08222024_080855.xml","form_type":"4"}},{"id":1426028,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-22T20:06:01.000Z","date":"2024-08-20","kind":"sale","planned":false,"acquired":false,"shares":135902,"price":31.95,"value":4342068.9,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-021998","document":"form4-08222024_080855.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924021998/form4-08222024_080855.xml","form_type":"4"}},{"id":1426027,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-22T20:06:01.000Z","date":"2024-08-20","kind":"exercise","planned":false,"acquired":true,"shares":135902,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 20, 2024, the reporting persons directed the sale of an aggregate of 135,902 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":135902,"source":{"system":"sec-edgar","filing":"0001415889-24-021998","document":"form4-08222024_080855.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924021998/form4-08222024_080855.xml","form_type":"4"}},{"id":1428365,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2024-08-20T21:44:44.000Z","date":"2024-08-16","kind":"exercise","planned":false,"acquired":true,"shares":242601,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"5. The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 16, 2024, the reporting persons directed the sale of an aggregate of 242,601 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"5. The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 16, 2024, the reporting persons directed the sale of an aggregate of 242,601 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"5. The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 16, 2024, the reporting persons directed the sale of an aggregate of 242,601 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 28,072,989 shares of Series B common stock held by Fund IX-A, (ii) 17,528,380 shares of Series B Common Stock held by Fund IX-B, (iii) 1,730,965 shares of Series B Common Stock held by Kiwi Co-Invest\nFund, (iv) 147,544 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 19,150 shares of Series B Common Stock held by Fund IX/VC IV (UK)"},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":47499028,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":242601},"source":{"system":"sec-edgar","filing":"0001415889-24-021709","document":"form4-08202024_090840.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924021709/form4-08202024_090840.xml","form_type":"4"}},{"id":1428364,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-20T21:44:44.000Z","date":"2024-08-16","kind":"sale","planned":false,"acquired":false,"shares":242601,"price":31.78,"value":7709859.78,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001415889-24-021709","document":"form4-08202024_090840.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924021709/form4-08202024_090840.xml","form_type":"4"}},{"id":1428363,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2024-08-20T21:44:44.000Z","date":"2024-08-16","kind":"exercise","planned":false,"acquired":true,"shares":242601,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"5. The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On August 16, 2024, the reporting persons directed the sale of an aggregate of 242,601 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":242601,"source":{"system":"sec-edgar","filing":"0001415889-24-021709","document":"form4-08202024_090840.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000141588924021709/form4-08202024_090840.xml","form_type":"4"}},{"id":1498782,"issuer":{"id":3936,"kind":"organization","name":"LifeStance Health Group, Inc.","symbol":"LFST"},"owners":[{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":1,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":2,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":3,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":4,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":76312,"kind":"organization","name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","position":5,"cik":"0001660981","reported_name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2024-05-29T21:19:46.000Z","date":"2024-05-24","kind":"sale","planned":false,"acquired":false,"shares":3802345,"price":5.89,"value":22395812.05,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents 2,328,399 shares sold by Summit Partners Growth Equity Fund IX-A, L.P., 1,453,820 shares sold by Summit Partners Growth Equity Fund IX-B, L.P., 16,253 shares sold by Summit Investors GE IX/VC IV, LLC, 2,173 shares sold by Summit Partners Entrepreneur Advisors Fund II, L.P., and 1,700 shares sold by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Represents 25,677,643 shares held by Summit Partners Growth Equity Fund IX-A, L.P., 16,032,765 shares held by Summit Partners Growth Equity Fund IX-B, L.P., 179,239 shares held by Summit Investors GE IX/VC IV, LLC, 23,961 shares held by Summit Partners Entrepreneur Advisors Fund II, L.P., and 18,750 shares held by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F3","text":"Summit Partners, L.P. is the managing member of Summit Partners GE IX, LLC, which is general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. and Summit Partners Growth Equity Fund IX-B, L.P. Summit Master Company, LLC is (i) the sole member of Summit Partners Entrepreneur Advisors GP II, LLC, which is the general partner of Summit Partners Entrepreneur Advisors Fund II, L.P. and (ii) the managing member of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC, and the general partner of Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F4","text":"Summit Master Company, LLC, as the sole member of Summit Partners Entrepreneur Advisors GP II, LLC and the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to LifeStance Health Group, Inc. Summit Partners, L.P., through a three-person investment committee, currently composed of Peter Y. Chung, Mark A. deLaar and Craig D. Frances, has voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Each of the Summit Funds, Mr. Chung, Mr. deLaar and Dr. Frances disclaim disclaims beneficial ownership of the shares, except, in each case, to the extent of such person's or entity's pecuniary interest therein."}],"balance_after":41932358,"source":{"system":"sec-edgar","filing":"0000950170-24-066078","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1634415/000095017024066078/ownership.xml","form_type":"4"}},{"id":1756625,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2023-10-23T21:10:52.000Z","date":"2023-10-23","kind":"exercise","planned":false,"acquired":false,"shares":1770318,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On October 23, 2023, the reporting persons directed the sale of an aggregate of 1,770,318 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On October 23, 2023, the reporting persons directed the sale of an aggregate of 1,770,318 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On October 23, 2023, the reporting persons directed the sale of an aggregate of 1,770,318 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 28,216,372 shares of Series B common stock held by Fund IX-A, (ii) 17,617,906 shares of Series B Common Stock held by Fund IX-B, (iii) 1,739,806 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 148,297 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 19,248 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":47741629,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":1770318},"source":{"system":"sec-edgar","filing":"0000899243-23-020017","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000089924323020017/doc4.xml","form_type":"4"}},{"id":1756624,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2023-10-23T21:10:52.000Z","date":"2023-10-23","kind":"sale","planned":false,"acquired":false,"shares":1770318,"price":28.3218,"value":50138592.3324,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000899243-23-020017","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000089924323020017/doc4.xml","form_type":"4"}},{"id":1756623,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2023-10-23T21:10:52.000Z","date":"2023-10-23","kind":"exercise","planned":false,"acquired":true,"shares":1770318,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\"), at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On October 23, 2023, the reporting persons directed the sale of an aggregate of 1,770,318 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\"). Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":1770318,"source":{"system":"sec-edgar","filing":"0000899243-23-020017","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000089924323020017/doc4.xml","form_type":"4"}},{"id":1775094,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series B Common Stock, par value $0.001 per share","published_at":"2023-09-22T20:21:18.000Z","date":"2023-09-22","kind":"exercise","planned":false,"acquired":false,"shares":4919165,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\") is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\") at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 22, 2023, the reporting persons directed the sale of an aggregate of 4,919,165 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\") is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\") at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 22, 2023, the reporting persons directed the sale of an aggregate of 4,919,165 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\") is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\") at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 22, 2023, the reporting persons directed the sale of an aggregate of 4,919,165 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 29,262,669 shares of Series B common stock held by Fund IX-A, (ii) 18,271,200 shares of Series B Common Stock held by Fund IX-B, (iii) 1,804,320 shares of Series B Common Stock held by Kiwi Co-Invest Fund, (iv) 153,796 shares of Series B Common Stock held by Fund IX/VC IV, and (v) 19,962 shares of Series B Common Stock held by Fund IX/VC IV (UK)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\").  Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":49511947,"derivative":{"underlying":"Series A Common Stock, par value $0.001 per share","underlying_shares":4919165},"source":{"system":"sec-edgar","filing":"0000899243-23-019428","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/830588/000089924323019428/doc4.xml","form_type":"4"}},{"id":1775093,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2023-09-22T20:21:18.000Z","date":"2023-09-22","kind":"sale","planned":false,"acquired":false,"shares":4919165,"price":28.3218,"value":139319607.297,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\").  Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0000899243-23-019428","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/830588/000089924323019428/doc4.xml","form_type":"4"}},{"id":1775092,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":23867,"kind":"organization","name":"SUMMIT PARTNERS L P","position":1,"cik":"0000830588","reported_name":"SUMMIT PARTNERS L P","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":2,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":3,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23870,"kind":"organization","name":"Summit Partners Co-Invest (Kiwi), LP","position":4,"cik":"0001830877","reported_name":"Summit Partners Co-Invest (Kiwi), LP","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":5,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":6,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Common Stock, par value $0.001 per share","published_at":"2023-09-22T20:21:18.000Z","date":"2023-09-22","kind":"exercise","planned":false,"acquired":true,"shares":4919165,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Series B common stock, par value $0.001 per share (\"Series B Common Stock\") is convertible into an equal number of shares of Series A common stock, par value $0.001 per share (\"Series A Common Stock\") at any time, at the holder's election, and has no expiration date. Each share of Series B Common Stock will automatically convert into Series A Common Stock upon the earlier of (i) the date specified by 66-2/3% of the outstanding shares of Series B Common Stock, voting as a single series; (ii) following the seventh anniversary of the closing of Klaviyo, Inc.'s (the \"Company\") initial public offering; or (iii) any transfer, whether or not for value, except for certain permitted transfers described in the Company's certificate of incorporation. On September 22, 2023, the reporting persons directed the sale of an aggregate of 4,919,165 shares of their Series B Common Stock, resulting in the automatic conversion of the shares into Series A Common Stock upon execution of the sale."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Summit Partners, L.P. is the manager of Summit Partners GE IX, LLC, which is the general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. (\"Fund IX-A\") and Summit Partners Growth Equity Fund IX-B, L.P. (\"Fund IX-B\"). Summit Partners, L.P. is the managing member of Summit Partners Co-Invest Kiwi GP, LLC, which is the general partner of Summit Partners Co-Invest (Kiwi), L.P. (\"Kiwi Co-Invest Fund\").  Summit Master Company, LLC is the general partner of Summit Partners, L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC (\"Fund IX/VC IV\") and the general partner of Summit Investors GE IX/VC IV (UK), L.P. (\"Fund IX/VC IV (UK)\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(continued from footnote 2) Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated voting and investment decisions with respect to the Series B Common Stock held by Fund IX/VC IV and Fund IX/VC IV (UK) to Summit Partners, L.P."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"The investment committee of Summit Partners, L.P., is currently composed of Peter Y. Chung, Scott C. Collins, and Peter L. Rottier, who may be deemed to have voting and dispositive authority over, and therefore beneficial ownership of, the reported securities. Each of the foregoing entities, Mr. Chung, Mr. Collins, and Mr. Rottier disclaims beneficial ownership of the shares, except to the extent of such person's or entity's pecuniary interest therein and the filing of this statement shall not be deemed an admission that any of the foregoing entities or persons are, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any equity securities covered by this statement."}],"balance_after":4919165,"source":{"system":"sec-edgar","filing":"0000899243-23-019428","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/830588/000089924323019428/doc4.xml","form_type":"4"}},{"id":2651124,"issuer":{"id":3936,"kind":"organization","name":"LifeStance Health Group, Inc.","symbol":"LFST"},"owners":[{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":1,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":2,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":3,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":4,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":76312,"kind":"organization","name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","position":5,"cik":"0001660981","reported_name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2021-06-29T21:22:09.000Z","date":"2021-06-25","kind":"sale","acquired":false,"shares":1140704,"price":17.01,"value":19403375.04,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents 698,520 shares sold by Summit Partners Growth Equity Fund IX-A, L.P., 436,146 shares sold by Summit Partners Growth Equity Fund IX-B, L.P., 4,876 shares sold by Summit Investors GE IX/VC IV, LLC, 652 shares sold by Summit Partners Entrepreneur Advisors Fund II, L.P., and 510 shares sold by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Represents 28,006,042 shares held by Summit Partners Growth Equity Fund IX-A, L.P., 17,486,585 shares held by Summit Partners Growth Equity Fund IX-B, L.P., 195,492 shares held by Summit Investors GE IX/VC IV, LLC, 26,134 shares held by Summit Partners Entrepreneur Advisors Fund II, L.P., and 20,450 shares held by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F3","text":"Summit Partners, L.P. is the managing member of Summit Partners GE IX, LLC, which is general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. and Summit Partners Growth Equity Fund IX-B, L.P. Summit Master Company, LLC is (i) the sole member of Summit Partners Entrepreneur Advisors GP II, LLC, which is the general partner of Summit Partners Entrepreneur Advisors Fund II, L.P. and (ii) the general partner of Summit Partners L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC, and the general partner of Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F4","text":"Summit Master Company, LLC, as the sole member of Summit Partners Entrepreneur Advisors GP II, LLC and the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to LifeStance Health Group, Inc. Summit Partners, L.P., through a three-person investment committee, currently composed of Peter Y. Chung, Mark A. deLaar and Craig D. Frances, has voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Each of the Summit Funds, Mr. Chung, Mr. deLaar and Dr. Frances disclaim disclaims beneficial ownership of the shares, except, in each case, to the extent of such person's or entity's pecuniary interest therein."}],"balance_after":45734703,"source":{"system":"sec-edgar","filing":"0001179110-21-007118","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1634415/000117911021007118/edgar.xml","form_type":"4"}},{"id":2665508,"issuer":{"id":3936,"kind":"organization","name":"LifeStance Health Group, Inc.","symbol":"LFST"},"owners":[{"id":23868,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-A, L.P.","position":1,"cik":"0001634415","reported_name":"Summit Partners Growth Equity Fund IX-A, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23869,"kind":"organization","name":"Summit Partners Growth Equity Fund IX-B, L.P.","position":2,"cik":"0001634426","reported_name":"Summit Partners Growth Equity Fund IX-B, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23872,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","position":3,"cik":"0001846709","reported_name":"SUMMIT INVESTORS GE IX/VC IV (UK), L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":23871,"kind":"organization","name":"SUMMIT INVESTORS GE IX/VC IV, LLC","position":4,"cik":"0001654074","reported_name":"SUMMIT INVESTORS GE IX/VC IV, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":76312,"kind":"organization","name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","position":5,"cik":"0001660981","reported_name":"Summit Partners Entrepreneur Advisors Fund II, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2021-06-16T20:47:33.000Z","date":"2021-06-14","kind":"sale","acquired":false,"shares":1368844,"price":17.01,"value":23284036.44,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents 838,224 shares sold by Summit Partners Growth Equity Fund IX-A, L.P., 523,375 shares sold by Summit Partners Growth Equity Fund IX-B, L.P., 5,851 shares sold by Summit Investors GE IX/VC IV, LLC, 782 shares sold by Summit Partners Entrepreneur Advisors Fund II, L.P., and 612 shares sold by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Represents 28,704,562 shares held by Summit Partners Growth Equity Fund IX-A, L.P., 17,922,731 shares held by Summit Partners Growth Equity Fund IX-B, L.P., 200,368 shares held by Summit Investors GE IX/VC IV, LLC, 26,786 shares held by Summit Partners Entrepreneur Advisors Fund II, L.P., and 20,960 shares held by Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F3","text":"Summit Partners, L.P. is the managing member of Summit Partners GE IX, LLC, which is general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. and Summit Partners Growth Equity Fund IX-B, L.P. Summit Master Company, LLC is (i) the sole member of Summit Partners Entrepreneur Advisors GP II, LLC, which is the general partner of Summit Partners Entrepreneur Advisors Fund II, L.P. and (ii) the general partner of Summit Partners L.P., which is the manager of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC, and the general partner of Summit Investors GE IX/VC IV (UK), L.P."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F4","text":"Summit Master Company, LLC, as the sole member of Summit Partners Entrepreneur Advisors GP II, LLC and the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to LifeStance Health Group, Inc. Summit Partners, L.P., through a three-person investment committee, currently composed of Peter Y. Chung, Mark A. deLaar and Craig D. Frances, has voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Each of the Summit Funds, Mr. Chung, Mr. deLaar and Dr. Frances disclaim disclaims beneficial ownership of the shares, except, in each case, to the extent of such person's or entity's pecuniary interest therein."}],"balance_after":46875407,"source":{"system":"sec-edgar","filing":"0001179110-21-006787","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1634415/000117911021006787/edgar.xml","form_type":"4"}}]}