{"transactions":[{"id":683753,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-08-18T21:19:27.000Z","date":"2026-08-17","kind":"tax_withholding","planned":false,"acquired":false,"shares":53878,"price":13.03,"value":702030.34,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on August 15, 2026, from the vesting of restricted stock units (\"RSUs\"), and does not represent a sale by the Reporting Person."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 774,628 RSUs."}],"balance_after":950316,"source":{"system":"sec-edgar","filing":"0001866692-26-000013","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000186669226000013/form4.xml","form_type":"4"}},{"id":711254,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2026-07-10T20:13:00.000Z","date":"2026-07-08","kind":"gift","planned":false,"acquired":true,"shares":175000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Spouse"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F2","text":"This transaction involved a gift of securities by the trust to the reporting person's spouse. This is not a market transaction, thus no price has been reported. No value was received for the gifted shares."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."}],"balance_after":175000,"derivative":{"underlying":"Class A Common Stock","underlying_shares":175000},"source":{"system":"sec-edgar","filing":"0001883022-26-000016","document":"primarydocument.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000016/primarydocument.xml","form_type":"4"}},{"id":711253,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2026-07-10T20:13:00.000Z","date":"2026-07-08","kind":"gift","planned":false,"acquired":false,"shares":175000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F2","text":"This transaction involved a gift of securities by the trust to the reporting person's spouse. This is not a market transaction, thus no price has been reported. No value was received for the gifted shares."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Securities held by a trust over which the reporting person exercises voting and dispositive control."}],"balance_after":7207208,"derivative":{"underlying":"Class A Common Stock","underlying_shares":175000},"source":{"system":"sec-edgar","filing":"0001883022-26-000016","document":"primarydocument.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000016/primarydocument.xml","form_type":"4"}},{"id":736406,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-06-16T21:15:11.000Z","date":"2026-06-01","kind":"sale","planned":true,"acquired":false,"shares":22786,"price":8.0259,"value":182878.1574,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on November 26, 2025."},{"field":"shares","element":"transactionShares","label":"F2","text":"This Form 4/A is being filed solely to correct the number of shares reported as sold on June 1, 2026 and the total number of shares owned following the transaction. Due to a broker administrative error, 585 fewer shares were sold than were required pursuant to the Reporting Person's Rule 10b5-1 trading plan. The error was corrected through the broker's error account, with the broker crediting the Reporting Person for the additional 585 shares at the applicable June 1, 2026 sale price and absorbing the cost of the correction. No additional open-market sale was effected in connection with the correction."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"This transaction was executed in multiple trades at prices ranging from $8.0000 to $8.0600. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Includes 880,520 restricted stock units."}],"balance_after":1004194,"source":{"system":"sec-edgar","filing":"0001610717-26-000228","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000161071726000228/form4.xml","form_type":"4/A","original_submission_date":"2026-06-03"}},{"id":752144,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-06-03T21:17:17.000Z","date":"2026-06-01","kind":"sale","planned":true,"acquired":false,"shares":22201,"price":8.0259,"value":178183.0059,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on November 26, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"This transaction was executed in multiple trades at prices ranging from $8.0000 to $8.0600. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 880,520 restricted stock units."}],"balance_after":1004779,"source":{"system":"sec-edgar","filing":"0001883022-26-000014","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000014/primarydocument.xml","form_type":"4"}},{"id":772381,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-05-19T20:28:32.000Z","date":"2026-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":40279,"price":6.06,"value":244090.74,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on May 15, 2026, from the vesting of restricted stock units (\"RSUs\"), and does not represent a sale by the Reporting Person."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 880,520 RSUs."}],"balance_after":1026980,"source":{"system":"sec-edgar","filing":"0001883022-26-000012","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000012/primarydocument.xml","form_type":"4"}},{"id":790063,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-05-06T20:52:37.000Z","date":"2026-05-04","kind":"sale","planned":true,"acquired":false,"shares":17586,"price":8.1245,"value":142877.457,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on November 26, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"This transaction was executed in multiple trades at prices ranging from $8.0000 to $8.2200. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 986,412 restricted stock units."}],"balance_after":1067259,"source":{"system":"sec-edgar","filing":"0001883022-26-000010","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000010/primarydocument.xml","form_type":"4"}},{"id":805823,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-04-17T21:55:12.000Z","date":"2026-04-15","kind":"grant","planned":false,"acquired":true,"shares":417827,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Each restricted stock unit (\"RSU\") represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in twelve substantially equal quarterly installments beginning on May 15, 2026, subject to the continued service of the reporting person through each vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 986,412 RSUs."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"The Form 4s filed by the reporting person on March 9, 2026 and March 10, 2026 understated the reporting person's beneficial ownership by 63,262 shares. The correct number of shares beneficially owned following the transaction on April 15, 2026 is reflected herein."}],"balance_after":1084845,"source":{"system":"sec-edgar","filing":"0001883022-26-000008","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000008/primarydocument.xml","form_type":"4"}},{"id":851305,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-03-10T20:54:06.000Z","date":"2026-03-06","kind":"sale","planned":true,"acquired":false,"shares":33201,"price":8.007,"value":265840.407,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the reporting person on November 26, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"This transaction was executed in multiple trades at prices ranging from $8.00 to $8.04. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 568,585 restricted stock units."}],"balance_after":603756,"source":{"system":"sec-edgar","filing":"0001883022-26-000006","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000006/primarydocument.xml","form_type":"4"}},{"id":853748,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-03-09T20:44:16.000Z","date":"2026-03-05","kind":"sale","planned":true,"acquired":false,"shares":30061,"price":8.0017,"value":240539.1037,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the reporting person on November 26, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"This transaction was executed in multiple trades in prices ranging from $8.00 to $8.02, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes 568,585 restricted stock units."}],"balance_after":636957,"source":{"system":"sec-edgar","filing":"0001883022-26-000005","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000005/primarydocument.xml","form_type":"4"}},{"id":901277,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2026-02-17T21:34:57.000Z","date":"2026-02-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":26672,"price":6.34,"value":169100.48,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on February 15, 2026, from the vesting of restricted stock units (\"RSUs\"), and does not represent a sale by the reporting person."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes  568,585 RSUs."}],"balance_after":730280,"source":{"system":"sec-edgar","filing":"0001883022-26-000002","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302226000002/primarydocument.xml","form_type":"4"}},{"id":996007,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2025-11-18T22:18:45.000Z","date":"2025-11-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":36092,"price":10.73,"value":387267.16,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on November 15, 2025, from the vesting of restricted stock units (\"RSUs\"), and does not represent a sale by the reporting person."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes  639,658 RSUs."}],"balance_after":756952,"source":{"system":"sec-edgar","filing":"0001883022-25-000003","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000188302225000003/primarydocument.xml","form_type":"4"}},{"id":1062024,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2025-08-19T21:44:28.000Z","date":"2025-08-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":34301,"price":11.47,"value":393432.47,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on August 15, 2025, from the vesting of restricted stock units (\"RSUs\"), and does not represent a sale by the reporting person."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 710,732 RSUs."}],"balance_after":793044,"source":{"system":"sec-edgar","filing":"0001562180-25-005897","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218025005897/primarydocument.xml","form_type":"4"}},{"id":1143083,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2025-05-19T21:22:54.000Z","date":"2025-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":25533,"price":12.14,"value":309970.62,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on May 15, 2025, from the vesting of restricted stock units (\"RSUs\"), and does not represent a sale by the reporting person."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 781,805 RSUs."}],"balance_after":827345,"source":{"system":"sec-edgar","filing":"0001562180-25-004004","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218025004004/primarydocument.xml","form_type":"4"}},{"id":1163974,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2025-04-29T20:59:20.000Z","date":"2025-04-25","kind":"grant","planned":false,"acquired":true,"shares":852878,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Each restricted stock unit (\"RSU\") represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in twelve substantially equal quarterly installments beginning on May 15, 2025, subject to the continued service of the reporting person through each vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of 852,878 RSUs."}],"balance_after":852878,"source":{"system":"sec-edgar","filing":"0001562180-25-003350","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218025003350/primarydocument.xml","form_type":"4"}},{"id":1659272,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2024-02-05T22:12:17.000Z","date":"2024-02-01","kind":"exercise","planned":false,"acquired":true,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F3","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F3","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Reflects the transfer of 23,866 shares by the Reporting Person to his trust."}],"balance_after":0,"derivative":{"underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0001562180-24-001049","document":"primarydocument.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218024001049/primarydocument.xml","form_type":"4"}},{"id":1659271,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Options (Right to buy)","published_at":"2024-02-05T22:12:17.000Z","date":"2024-02-01","kind":"exercise","planned":false,"acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"1/48th of the shares subject to the option vest on each monthly anniversary measured from January 1, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date."}],"balance_after":12199,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0001562180-24-001049","document":"primarydocument.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218024001049/primarydocument.xml","form_type":"4"}},{"id":1659270,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2024-02-05T22:12:17.000Z","date":"2024-02-01","kind":"exercise","planned":false,"acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001562180-24-001049","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218024001049/primarydocument.xml","form_type":"4"}},{"id":1659269,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2024-02-05T22:12:17.000Z","date":"2024-02-01","kind":"exercise","planned":false,"acquired":true,"shares":23866,"price":4.19,"value":99998.54,"ownership":{"direct":true},"balance_after":23866,"source":{"system":"sec-edgar","filing":"0001562180-24-001049","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218024001049/primarydocument.xml","form_type":"4"}},{"id":2033449,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2023-02-03T23:28:29.000Z","date":"2023-02-01","kind":"exercise","acquired":true,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F3","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F3","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Reflects the transfer of 23,866 shares by the Reporting Person to his trust."}],"balance_after":0,"derivative":{"underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0001562180-23-000989","document":"primarydocument.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218023000989/primarydocument.xml","form_type":"4"}},{"id":2033448,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Options (Right to buy)","published_at":"2023-02-03T23:28:29.000Z","date":"2023-02-01","kind":"exercise","acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"1/48th of the shares subject to the option vest on each monthly anniversary measured from January 1, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date."}],"balance_after":36065,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0001562180-23-000989","document":"primarydocument.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218023000989/primarydocument.xml","form_type":"4"}},{"id":2033447,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2023-02-03T23:28:29.000Z","date":"2023-02-01","kind":"exercise","acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001562180-23-000989","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218023000989/primarydocument.xml","form_type":"4"}},{"id":2033446,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2023-02-03T23:28:29.000Z","date":"2023-02-01","kind":"exercise","acquired":true,"shares":23866,"price":4.19,"value":99998.54,"ownership":{"direct":true},"balance_after":23866,"source":{"system":"sec-edgar","filing":"0001562180-23-000989","document":"primarydocument.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156218023000989/primarydocument.xml","form_type":"4"}},{"id":2379089,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":true,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F5","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six- month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F2","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six- month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F5","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six- month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Reflects the transfer of 23,866 shares by the Reporting Person to his trust."}],"balance_after":0,"derivative":{"underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379088,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":true,"shares":70000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F5","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six- month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F2","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six- month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F5","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six- month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Reflects the transfer of 23,866 shares by the Reporting Person to his trust."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":7334476,"derivative":{"underlying":"Class A Common Stock","underlying_shares":70000},"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379087,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"1/48th of the shares subject to the option vest on each monthly anniversary measured from January 1, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date."}],"balance_after":59931,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379086,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":false,"shares":70000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The option is early exercisable. 1/24th of the shares subject to the option vest on each monthly anniversary measured from September 21, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested on the second anniversary of the Vesting Commencement Date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":515515,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Class A Common Stock","underlying_shares":70000},"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379085,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F2","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379084,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":false,"shares":70000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F2","text":"Represents the conversion of Class A Common Stock into the Issuer's Class B Common Stock effected pursuant to an amendment to the Issuer's Amended and Restated 2014 Stock Option and Grant Plan, which gave holders a one-time right to exchange such shares of Class A Common Stock for an equal number of shares of Class B Common Stock."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":79228,"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379083,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":true,"shares":23866,"price":4.19,"value":99998.54,"ownership":{"direct":true},"balance_after":23866,"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2379082,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2022-02-23T23:14:48.000Z","date":"2022-02-17","kind":"exercise","acquired":true,"shares":70000,"price":4.19,"value":293300.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":149228,"source":{"system":"sec-edgar","filing":"0001567619-22-005406","document":"doc1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000156761922005406/doc1.xml","form_type":"4"}},{"id":2555953,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2021-09-30T23:32:29.000Z","date":"2021-09-28","kind":"sale","acquired":false,"shares":142000,"price":50.91,"value":7229220.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":79228,"source":{"system":"sec-edgar","filing":"0000899243-21-038472","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321038472/doc4.xml","form_type":"4"}},{"id":2555952,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2021-09-30T23:32:29.000Z","date":"2021-09-28","kind":"sale","acquired":false,"shares":158772,"price":50,"value":7938600.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":221228,"source":{"system":"sec-edgar","filing":"0000899243-21-038472","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321038472/doc4.xml","form_type":"4"}},{"id":2561163,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2021-09-24T01:30:19.000Z","date":"2021-08-30","kind":"exercise","acquired":true,"shares":155084,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"security","element":"securityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":7620610,"derivative":{"underlying":"Class A Common Stock","underlying_shares":155084},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":9,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561162,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2021-09-24T01:30:19.000Z","date":"2021-08-30","kind":"exercise","acquired":false,"shares":155084,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"The option is early exercisable.  1/48th of the shares subject to the option vest on each monthly anniversary measured from January 1, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested on the fourth anniversary of the Vesting Commencement Date."},{"field":"derivative.underlying","element":"underlyingSecurityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":117768,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Common Stock","underlying_shares":155084},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561161,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2021-09-24T01:30:19.000Z","date":"2021-06-28","kind":"gift","acquired":false,"shares":475000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"security","element":"securityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":7465526,"derivative":{"underlying":"Class A Common Stock","underlying_shares":475000},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561160,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2021-09-24T01:30:19.000Z","date":"2021-06-24","kind":"exercise","acquired":true,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"security","element":"securityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":7940526,"derivative":{"underlying":"Class A Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561159,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2021-09-24T01:30:19.000Z","date":"2021-06-24","kind":"exercise","acquired":false,"shares":23866,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F6","text":"1/48th of the shares subject to the option vest on each monthly anniversary measured from January 1, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date."},{"field":"derivative.underlying","element":"underlyingSecurityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."}],"balance_after":83797,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Common Stock","underlying_shares":23866},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561158,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2021-09-24T01:30:19.000Z","date":"2021-06-24","kind":"exercise","acquired":true,"shares":105000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"security","element":"securityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":7916660,"derivative":{"underlying":"Class A Common Stock","underlying_shares":105000},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561157,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2021-09-24T01:30:19.000Z","date":"2021-06-24","kind":"exercise","acquired":false,"shares":105000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Transaction is being reported herein pursuant to Rule 16a-2(a)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"The option is early exercisable.  1/48th of the shares subject to the option vest on each monthly anniversary measured from January 1, 2021 (the \"Vesting Commencement Date\"), such that 100% of the shares subject to the option will be fully vested on the fourth anniversary of the Vesting Commencement Date."},{"field":"derivative.underlying","element":"underlyingSecurityTitle","label":"F5","text":"In connection with the reclassification of the Issuer's Common Stock on August 30, 2021, each share of Common Stock held by the Reporting Person was automatically reclassified as Class B Common Stock."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":272852,"derivative":{"exercise_price":4.19,"expiration_date":"2030-12-28","underlying":"Common Stock","underlying_shares":105000},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561156,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class B Common Stock","published_at":"2021-09-24T01:30:19.000Z","date":"2021-09-21","kind":"exercise","acquired":false,"shares":380000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":7240610,"derivative":{"underlying":"Class A Common Stock","underlying_shares":380000},"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}},{"id":2561155,"issuer":{"id":4566,"kind":"organization","name":"Amplitude, Inc.","symbol":"AMPL"},"owners":[{"id":22313,"kind":"person","name":"Liu Curtis","position":1,"cik":"0001883022","reported_name":"Liu Curtis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Technology Officer"}}],"security":"Class A Common Stock","published_at":"2021-09-24T01:30:19.000Z","date":"2021-09-21","kind":"exercise","acquired":true,"shares":380000,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Trust"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of the holder, (c) the date that is six months following the date on which the holder is no longer an employee or director of the Issuer (unless such holder has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period)."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Securities held by a trust over which the Reporting Person exercises voting and dispositive control."}],"balance_after":380000,"source":{"system":"sec-edgar","filing":"0000899243-21-037513","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1883022/000089924321037513/doc4.xml","form_type":"4"}}]}