{"transactions":[{"id":734151,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-17","kind":"exercise","planned":false,"acquired":false,"shares":13040,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option vested in full on the date of the 2026 annual stockholder meeting."}],"balance_after":0,"derivative":{"exercise_price":1.07,"expiration_date":"2035-06-04","underlying":"Common Stock","underlying_shares":13040},"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":734150,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-15","kind":"exercise","planned":false,"acquired":false,"shares":6460,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option vested in full on the date of the 2026 annual stockholder meeting."}],"balance_after":13040,"derivative":{"exercise_price":1.07,"expiration_date":"2035-06-04","underlying":"Common Stock","underlying_shares":6460},"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":734149,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-17","kind":"sale","planned":false,"acquired":false,"shares":13040,"price":2.325,"value":30318.0,"ownership":{"direct":true},"balance_after":35500,"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":734148,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-17","kind":"exercise","planned":false,"acquired":true,"shares":13040,"price":1.07,"value":13952.8,"ownership":{"direct":true},"balance_after":48540,"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":734147,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-16","kind":"sale","planned":false,"acquired":false,"shares":12800,"price":2.326,"value":29772.8,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $2.305 to $2.345. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":35500,"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":734146,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-15","kind":"sale","planned":false,"acquired":false,"shares":6460,"price":2.345,"value":15148.7,"ownership":{"direct":true},"balance_after":48300,"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":734145,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T21:10:15.000Z","date":"2026-06-15","kind":"exercise","planned":false,"acquired":true,"shares":6460,"price":1.07,"value":6912.2,"ownership":{"direct":true},"balance_after":54760,"source":{"system":"sec-edgar","filing":"0001628280-26-043987","document":"wk-form4_1781730613.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026043987/wk-form4_1781730613.xml","form_type":"4"}},{"id":743304,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":39704,"kind":"person","name":"Fountain Nathan B","position":1,"cik":"0001869596","reported_name":"Fountain Nathan B","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-10T20:51:13.000Z","date":"2026-06-09","kind":"sale","planned":false,"acquired":false,"shares":6400,"price":2.2301,"value":14272.64,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $2.2300 to $2.2311. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":48150,"source":{"system":"sec-edgar","filing":"0001628280-26-042280","document":"wk-form4_1781124671.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1869596/000162828026042280/wk-form4_1781124671.xml","form_type":"4"}},{"id":747665,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":19524,"kind":"organization","name":"RA CAPITAL MANAGEMENT, L.P.","position":1,"cik":"0001346824","reported_name":"RA CAPITAL MANAGEMENT, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19525,"kind":"organization","name":"RA Capital Healthcare Fund LP","position":2,"cik":"0001315082","reported_name":"RA Capital Healthcare Fund LP","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":29189,"kind":"person","name":"RA Capital Nexus Fund II, L.P.","position":3,"cik":"0001825376","reported_name":"RA Capital Nexus Fund II, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":19526,"kind":"person","name":"Kolchinsky Peter","position":4,"cik":"0001384859","reported_name":"Kolchinsky Peter","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19527,"kind":"person","name":"Shah Rajeev M.","position":5,"cik":"0001619841","reported_name":"Shah Rajeev M.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2026-06-05T21:12:37.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See Footnotes"},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"Represents the award of an option to Dr. Stoppel. The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to Dr. Stoppel's continuous service through such vesting date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"RA Capital Management, L.P. (the \"Adviser\") is the investment manager for RA Capital Healthcare Fund, L.P. (the \"Fund\"), RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The general partner of the Adviser is RA Capital Management GP, LLC (the \"Adviser GP\"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Under Dr. Stoppel's arrangement with the Adviser, Dr. Stoppel holds the RSUs and the option for the benefit of the Fund, the Nexus Fund II and the Account. Dr. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSUs, as applicable, which will offset advisory fees owed by the Fund, the Nexus Fund II and the Account to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the RSUs, the option and the underlying common stock."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001231919-26-000604","document":"form4-06052026_090630.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1315082/000123191926000604/form4-06052026_090630.xml","form_type":"4"}},{"id":747664,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":19524,"kind":"organization","name":"RA CAPITAL MANAGEMENT, L.P.","position":1,"cik":"0001346824","reported_name":"RA CAPITAL MANAGEMENT, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19525,"kind":"organization","name":"RA Capital Healthcare Fund LP","position":2,"cik":"0001315082","reported_name":"RA Capital Healthcare Fund LP","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":29189,"kind":"person","name":"RA Capital Nexus Fund II, L.P.","position":3,"cik":"0001825376","reported_name":"RA Capital Nexus Fund II, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":19526,"kind":"person","name":"Kolchinsky Peter","position":4,"cik":"0001384859","reported_name":"Kolchinsky Peter","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19527,"kind":"person","name":"Shah Rajeev M.","position":5,"cik":"0001619841","reported_name":"Shah Rajeev M.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T21:12:37.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award to Laura Stoppel. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to Dr. Stoppel's continuous service through such vesting date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"RA Capital Management, L.P. (the \"Adviser\") is the investment manager for RA Capital Healthcare Fund, L.P. (the \"Fund\"), RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The general partner of the Adviser is RA Capital Management GP, LLC (the \"Adviser GP\"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Under Dr. Stoppel's arrangement with the Adviser, Dr. Stoppel holds the RSUs and the option for the benefit of the Fund, the Nexus Fund II and the Account. Dr. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSUs, as applicable, which will offset advisory fees owed by the Fund, the Nexus Fund II and the Account to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the RSUs, the option and the underlying common stock."}],"balance_after":48300,"source":{"system":"sec-edgar","filing":"0001231919-26-000604","document":"form4-06052026_090630.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1315082/000123191926000604/form4-06052026_090630.xml","form_type":"4"}},{"id":748205,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":39704,"kind":"person","name":"Fountain Nathan B","position":1,"cik":"0001869596","reported_name":"Fountain Nathan B","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:32:22.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041281","document":"wk-form4_1780691540.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1869596/000162828026041281/wk-form4_1780691540.xml","form_type":"4"}},{"id":748204,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":39704,"kind":"person","name":"Fountain Nathan B","position":1,"cik":"0001869596","reported_name":"Fountain Nathan B","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:32:22.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":54550,"source":{"system":"sec-edgar","filing":"0001628280-26-041281","document":"wk-form4_1780691540.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1869596/000162828026041281/wk-form4_1780691540.xml","form_type":"4"}},{"id":747622,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":38204,"kind":"person","name":"Drapkin Kimberlee C","position":1,"cik":"0001340881","reported_name":"Drapkin Kimberlee C","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:31:35.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041276","document":"wk-form4_1780691492.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1340881/000162828026041276/wk-form4_1780691492.xml","form_type":"4"}},{"id":747621,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":38204,"kind":"person","name":"Drapkin Kimberlee C","position":1,"cik":"0001340881","reported_name":"Drapkin Kimberlee C","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:31:35.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":48300,"source":{"system":"sec-edgar","filing":"0001628280-26-041276","document":"wk-form4_1780691492.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1340881/000162828026041276/wk-form4_1780691492.xml","form_type":"4"}},{"id":747512,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40808,"kind":"person","name":"Stalfort John A III","position":1,"cik":"0001709418","reported_name":"Stalfort John A III","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:30:52.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041273","document":"wk-form4_1780691449.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026041273/wk-form4_1780691449.xml","form_type":"4"}},{"id":747511,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40808,"kind":"person","name":"Stalfort John A III","position":1,"cik":"0001709418","reported_name":"Stalfort John A III","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:30:52.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":220624,"source":{"system":"sec-edgar","filing":"0001628280-26-041273","document":"wk-form4_1780691449.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026041273/wk-form4_1780691449.xml","form_type":"4"}},{"id":747974,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:30:12.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041272","document":"wk-form4_1780691403.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026041272/wk-form4_1780691403.xml","form_type":"4"}},{"id":747973,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":37267,"kind":"person","name":"Porter Derrell","position":1,"cik":"0001706400","reported_name":"Porter Derrell","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:30:12.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":48300,"source":{"system":"sec-edgar","filing":"0001628280-26-041272","document":"wk-form4_1780691403.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1706400/000162828026041272/wk-form4_1780691403.xml","form_type":"4"}},{"id":747510,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40807,"kind":"person","name":"Ives Jeffrey L.","position":1,"cik":"0001614096","reported_name":"Ives Jeffrey L.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:29:28.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041270","document":"wk-form4_1780691363.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026041270/wk-form4_1780691363.xml","form_type":"4"}},{"id":747509,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40807,"kind":"person","name":"Ives Jeffrey L.","position":1,"cik":"0001614096","reported_name":"Ives Jeffrey L.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:29:28.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":48300,"source":{"system":"sec-edgar","filing":"0001628280-26-041270","document":"wk-form4_1780691363.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026041270/wk-form4_1780691363.xml","form_type":"4"}},{"id":747508,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40806,"kind":"person","name":"Golumbeski George","position":1,"cik":"0001586660","reported_name":"Golumbeski George","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:28:38.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041268","document":"wk-form4_1780691316.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026041268/wk-form4_1780691316.xml","form_type":"4"}},{"id":747507,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40806,"kind":"person","name":"Golumbeski George","position":1,"cik":"0001586660","reported_name":"Golumbeski George","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:28:38.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":35500,"source":{"system":"sec-edgar","filing":"0001628280-26-041268","document":"wk-form4_1780691316.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026041268/wk-form4_1780691316.xml","form_type":"4"}},{"id":748187,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40979,"kind":"person","name":"Stoppel Laura","position":1,"cik":"0001865119","reported_name":"Stoppel Laura","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2026-06-05T20:27:28.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":53250,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"Under the Reporting Person's arrangement with RA Capital Management, L.P. (the \"Adviser\"), the Reporting Person holds the option and RSUs for the benefit of the RA Capital Healthcare Fund, L.P. (the \"Fund\"), RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSUs, as applicable, which will offset advisory fees owed by the Fund, the Nexus Fund II and the Account to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the option and RSUs and underlying common stock."}],"balance_after":53250,"derivative":{"exercise_price":2.29,"expiration_date":"2036-06-03","underlying":"Common Stock","underlying_shares":53250},"source":{"system":"sec-edgar","filing":"0001628280-26-041263","document":"wk-form4_1780691244.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1865119/000162828026041263/wk-form4_1780691244.xml","form_type":"4"}},{"id":748186,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40979,"kind":"person","name":"Stoppel Laura","position":1,"cik":"0001865119","reported_name":"Stoppel Laura","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-05T20:27:28.000Z","date":"2026-06-03","kind":"grant","planned":false,"acquired":true,"shares":35500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2027 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"Under the Reporting Person's arrangement with RA Capital Management, L.P. (the \"Adviser\"), the Reporting Person holds the option and RSUs for the benefit of the RA Capital Healthcare Fund, L.P. (the \"Fund\"), RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSUs, as applicable, which will offset advisory fees owed by the Fund, the Nexus Fund II and the Account to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the option and RSUs and underlying common stock."}],"balance_after":48300,"source":{"system":"sec-edgar","filing":"0001628280-26-041263","document":"wk-form4_1780691244.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1865119/000162828026041263/wk-form4_1780691244.xml","form_type":"4"}},{"id":834703,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":19524,"kind":"organization","name":"RA CAPITAL MANAGEMENT, L.P.","position":1,"cik":"0001346824","reported_name":"RA CAPITAL MANAGEMENT, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19525,"kind":"organization","name":"RA Capital Healthcare Fund LP","position":2,"cik":"0001315082","reported_name":"RA Capital Healthcare Fund LP","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":29189,"kind":"person","name":"RA Capital Nexus Fund II, L.P.","position":3,"cik":"0001825376","reported_name":"RA Capital Nexus Fund II, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":19526,"kind":"person","name":"Kolchinsky Peter","position":4,"cik":"0001384859","reported_name":"Kolchinsky Peter","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19527,"kind":"person","name":"Shah Rajeev M.","position":5,"cik":"0001619841","reported_name":"Shah Rajeev M.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2026-03-18T20:15:17.000Z","date":"2026-03-16","kind":"grant","planned":false,"acquired":true,"shares":6060606,"price":3.3,"value":19999999.8,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Held directly by RA Capital Healthcare Fund, L.P. (the \"Fund\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"RA Capital Management, L.P. (the \"Adviser\") is the investment manager for the Fund, RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The general partner of the Adviser is RA Capital Management GP, LLC (the \"Adviser GP\"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein."}],"balance_after":19103785,"source":{"system":"sec-edgar","filing":"0001231919-26-000262","document":"form4-03182026_040301.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1315082/000123191926000262/form4-03182026_040301.xml","form_type":"4"}},{"id":851070,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-03-10T21:45:26.000Z","date":"2026-03-06","kind":"exercise","planned":true,"acquired":false,"shares":2090,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":71048,"derivative":{"exercise_price":1.85,"expiration_date":"2035-01-06","underlying":"Common Stock","underlying_shares":2090},"source":{"system":"sec-edgar","filing":"0001628280-26-016645","document":"wk-form4_1773193523.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026016645/wk-form4_1773193523.xml","form_type":"4"}},{"id":851069,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-03-10T21:45:26.000Z","date":"2026-03-06","kind":"sale","planned":true,"acquired":false,"shares":2090,"price":3.26,"value":6813.4,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The reported sales occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."}],"balance_after":173999,"source":{"system":"sec-edgar","filing":"0001628280-26-016645","document":"wk-form4_1773193523.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026016645/wk-form4_1773193523.xml","form_type":"4"}},{"id":851068,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-03-10T21:45:26.000Z","date":"2026-03-06","kind":"exercise","planned":true,"acquired":true,"shares":2090,"price":1.85,"value":3866.5,"ownership":{"direct":true},"balance_after":176089,"source":{"system":"sec-edgar","filing":"0001628280-26-016645","document":"wk-form4_1773193523.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026016645/wk-form4_1773193523.xml","form_type":"4"}},{"id":867642,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-03-03T21:42:29.000Z","date":"2026-02-27","kind":"exercise","planned":true,"acquired":false,"shares":9406,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The shares subject to the employee stock option vest in 48 equal monthly installments starting on the date the option was granted, such that the option will be fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":73138,"derivative":{"exercise_price":1.85,"expiration_date":"2035-01-06","underlying":"Common Stock","underlying_shares":9406},"source":{"system":"sec-edgar","filing":"0001628280-26-014365","document":"wk-form4_1772592146.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026014365/wk-form4_1772592146.xml","form_type":"4"}},{"id":867641,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-03-03T21:42:29.000Z","date":"2026-02-27","kind":"sale","planned":true,"acquired":false,"shares":9406,"price":3.0099,"value":28311.1194,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The reported sales occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $3.0000 to $3.0300. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":173999,"source":{"system":"sec-edgar","filing":"0001628280-26-014365","document":"wk-form4_1772592146.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026014365/wk-form4_1772592146.xml","form_type":"4"}},{"id":867640,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-03-03T21:42:29.000Z","date":"2026-02-27","kind":"exercise","planned":true,"acquired":true,"shares":9406,"price":1.85,"value":17401.1,"ownership":{"direct":true},"balance_after":183405,"source":{"system":"sec-edgar","filing":"0001628280-26-014365","document":"wk-form4_1772592146.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026014365/wk-form4_1772592146.xml","form_type":"4"}},{"id":929006,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-28T19:50:04.000Z","date":"2026-01-28","kind":"exercise","planned":true,"acquired":false,"shares":2671,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The shares subject to the employee stock option vest in 48 equal monthly installments starting on the date the option was granted, such that the option will be fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":82544,"derivative":{"exercise_price":1.85,"expiration_date":"2035-01-06","underlying":"Common Stock","underlying_shares":2671},"source":{"system":"sec-edgar","filing":"0001628280-26-003948","document":"wk-form4_1769647801.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003948/wk-form4_1769647801.xml","form_type":"4"}},{"id":929005,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-28T19:50:04.000Z","date":"2026-01-26","kind":"exercise","planned":true,"acquired":false,"shares":15085,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The shares subject to the employee stock option vest in 48 equal monthly installments starting on the date the option was granted, such that the option will be fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":85215,"derivative":{"exercise_price":1.85,"expiration_date":"2035-01-06","underlying":"Common Stock","underlying_shares":15085},"source":{"system":"sec-edgar","filing":"0001628280-26-003948","document":"wk-form4_1769647801.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003948/wk-form4_1769647801.xml","form_type":"4"}},{"id":929004,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-28T19:50:04.000Z","date":"2026-01-28","kind":"sale","planned":true,"acquired":false,"shares":2671,"price":3.0016,"value":8017.2736,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The reported sales occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $3.0000 to $3.0100. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":173999,"source":{"system":"sec-edgar","filing":"0001628280-26-003948","document":"wk-form4_1769647801.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003948/wk-form4_1769647801.xml","form_type":"4"}},{"id":929003,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-28T19:50:04.000Z","date":"2026-01-28","kind":"exercise","planned":true,"acquired":true,"shares":2671,"price":1.85,"value":4941.35,"ownership":{"direct":true},"balance_after":176670,"source":{"system":"sec-edgar","filing":"0001628280-26-003948","document":"wk-form4_1769647801.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003948/wk-form4_1769647801.xml","form_type":"4"}},{"id":929002,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-28T19:50:04.000Z","date":"2026-01-26","kind":"sale","planned":true,"acquired":false,"shares":15085,"price":3.0005,"value":45262.5425,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The reported sales occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $3.0000 to $3.0100. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":173999,"source":{"system":"sec-edgar","filing":"0001628280-26-003948","document":"wk-form4_1769647801.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003948/wk-form4_1769647801.xml","form_type":"4"}},{"id":929001,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-28T19:50:04.000Z","date":"2026-01-26","kind":"exercise","planned":true,"acquired":true,"shares":15085,"price":1.85,"value":27907.25,"ownership":{"direct":true},"balance_after":189084,"source":{"system":"sec-edgar","filing":"0001628280-26-003948","document":"wk-form4_1769647801.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003948/wk-form4_1769647801.xml","form_type":"4"}},{"id":932014,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-23T23:11:25.000Z","date":"2026-01-22","kind":"sale","planned":false,"acquired":false,"shares":1687,"price":1.86,"value":3137.82,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."}],"balance_after":304924,"source":{"system":"sec-edgar","filing":"0001628280-26-003347","document":"wk-form4_1769209883.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026003347/wk-form4_1769209883.xml","form_type":"4"}},{"id":932013,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-23T23:11:25.000Z","date":"2026-01-21","kind":"sale","planned":false,"acquired":false,"shares":2473,"price":1.8072,"value":4469.2056,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7650 to $1.8700. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":306611,"source":{"system":"sec-edgar","filing":"0001628280-26-003347","document":"wk-form4_1769209883.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026003347/wk-form4_1769209883.xml","form_type":"4"}},{"id":932012,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-23T23:10:06.000Z","date":"2026-01-22","kind":"sale","planned":false,"acquired":false,"shares":462,"price":1.84,"value":850.08,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."}],"balance_after":205092,"source":{"system":"sec-edgar","filing":"0001628280-26-003344","document":"wk-form4_1769209803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026003344/wk-form4_1769209803.xml","form_type":"4"}},{"id":932011,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-23T23:10:06.000Z","date":"2026-01-21","kind":"sale","planned":false,"acquired":false,"shares":2315,"price":1.806,"value":4180.89,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7600 to $1.8700. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":205554,"source":{"system":"sec-edgar","filing":"0001628280-26-003344","document":"wk-form4_1769209803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026003344/wk-form4_1769209803.xml","form_type":"4"}},{"id":932389,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-23T18:12:54.000Z","date":"2026-01-23","kind":"sale","planned":false,"acquired":false,"shares":5633,"price":1.9027,"value":10717.9091,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.8800 to $1.9400. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":173999,"source":{"system":"sec-edgar","filing":"0001628280-26-003349","document":"wk-form4_1769209972.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003349/wk-form4_1769209972.xml","form_type":"4"}},{"id":932388,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-23T18:12:54.000Z","date":"2026-01-22","kind":"sale","planned":false,"acquired":false,"shares":1054,"price":1.84,"value":1939.36,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 15, 2024."}],"balance_after":179632,"source":{"system":"sec-edgar","filing":"0001628280-26-003349","document":"wk-form4_1769209972.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003349/wk-form4_1769209972.xml","form_type":"4"}},{"id":932387,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-23T18:12:54.000Z","date":"2026-01-21","kind":"sale","planned":false,"acquired":false,"shares":2247,"price":1.8083,"value":4063.2501,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 15, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7600 to $1.8700. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":180686,"source":{"system":"sec-edgar","filing":"0001628280-26-003349","document":"wk-form4_1769209972.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026003349/wk-form4_1769209972.xml","form_type":"4"}},{"id":932462,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68913,"kind":"person","name":"Siemers Eric","position":1,"cik":"0001866239","reported_name":"Siemers Eric","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Medical Officer"}}],"security":"Common Stock","published_at":"2026-01-23T18:12:03.000Z","date":"2026-01-22","kind":"sale","planned":false,"acquired":false,"shares":895,"price":1.82,"value":1628.9,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 3, 2024."}],"balance_after":255371,"source":{"system":"sec-edgar","filing":"0001628280-26-003348","document":"wk-form4_1769209918.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1866239/000162828026003348/wk-form4_1769209918.xml","form_type":"4"}},{"id":932461,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68913,"kind":"person","name":"Siemers Eric","position":1,"cik":"0001866239","reported_name":"Siemers Eric","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Medical Officer"}}],"security":"Common Stock","published_at":"2026-01-23T18:12:03.000Z","date":"2026-01-21","kind":"sale","planned":false,"acquired":false,"shares":2331,"price":1.8035,"value":4203.9585,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 3, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7600 to $1.8700. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":256266,"source":{"system":"sec-edgar","filing":"0001628280-26-003348","document":"wk-form4_1769209918.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1866239/000162828026003348/wk-form4_1769209918.xml","form_type":"4"}},{"id":932459,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-23T18:10:48.000Z","date":"2026-01-22","kind":"sale","planned":false,"acquired":false,"shares":2689,"price":1.8838,"value":5065.5382,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.8700 to $1.9000. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":881275,"source":{"system":"sec-edgar","filing":"0001628280-26-003346","document":"wk-form4_1769209845.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026003346/wk-form4_1769209845.xml","form_type":"4"}},{"id":932458,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-23T18:10:48.000Z","date":"2026-01-21","kind":"sale","planned":false,"acquired":false,"shares":9346,"price":1.8112,"value":16927.4752,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7600 to $1.8800. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":883964,"source":{"system":"sec-edgar","filing":"0001628280-26-003346","document":"wk-form4_1769209845.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026003346/wk-form4_1769209845.xml","form_type":"4"}},{"id":934035,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T23:32:05.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":148700,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":148700,"derivative":{"exercise_price":1.89,"expiration_date":"2036-01-16","underlying":"Common Stock","underlying_shares":148700},"source":{"system":"sec-edgar","filing":"0001628280-26-002961","document":"wk-form4_1769038322.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026002961/wk-form4_1769038322.xml","form_type":"4"}},{"id":934034,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-21T23:32:05.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":99133,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":309084,"source":{"system":"sec-edgar","filing":"0001628280-26-002961","document":"wk-form4_1769038322.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026002961/wk-form4_1769038322.xml","form_type":"4"}},{"id":934033,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T23:30:23.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":126900,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":126900,"derivative":{"exercise_price":1.89,"expiration_date":"2036-01-16","underlying":"Common Stock","underlying_shares":126900},"source":{"system":"sec-edgar","filing":"0001628280-26-002958","document":"wk-form4_1769038220.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026002958/wk-form4_1769038220.xml","form_type":"4"}},{"id":934032,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-21T23:30:23.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":84600,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":207869,"source":{"system":"sec-edgar","filing":"0001628280-26-002958","document":"wk-form4_1769038220.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026002958/wk-form4_1769038220.xml","form_type":"4"}},{"id":934367,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T18:32:39.000Z","date":"2026-01-20","kind":"grant","planned":false,"acquired":true,"shares":450000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":450000,"derivative":{"exercise_price":1.86,"expiration_date":"2036-01-20","underlying":"Common Stock","underlying_shares":450000},"source":{"system":"sec-edgar","filing":"0001628280-26-002962","document":"wk-form4_1769038356.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026002962/wk-form4_1769038356.xml","form_type":"4"}},{"id":934366,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-21T18:32:39.000Z","date":"2026-01-20","kind":"grant","planned":false,"acquired":true,"shares":299800,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":893310,"source":{"system":"sec-edgar","filing":"0001628280-26-002962","document":"wk-form4_1769038356.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026002962/wk-form4_1769038356.xml","form_type":"4"}},{"id":934304,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T18:31:39.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":148700,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":148700,"derivative":{"exercise_price":1.89,"expiration_date":"2036-01-16","underlying":"Common Stock","underlying_shares":148700},"source":{"system":"sec-edgar","filing":"0001628280-26-002960","document":"wk-form4_1769038296.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026002960/wk-form4_1769038296.xml","form_type":"4"}},{"id":934303,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-21T18:31:39.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":99133,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":182933,"source":{"system":"sec-edgar","filing":"0001628280-26-002960","document":"wk-form4_1769038296.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026002960/wk-form4_1769038296.xml","form_type":"4"}},{"id":934374,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68913,"kind":"person","name":"Siemers Eric","position":1,"cik":"0001866239","reported_name":"Siemers Eric","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Medical Officer"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T18:31:11.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":148700,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":148700,"derivative":{"exercise_price":1.89,"expiration_date":"2036-01-16","underlying":"Common Stock","underlying_shares":148700},"source":{"system":"sec-edgar","filing":"0001628280-26-002959","document":"wk-form4_1769038268.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1866239/000162828026002959/wk-form4_1769038268.xml","form_type":"4"}},{"id":934373,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68913,"kind":"person","name":"Siemers Eric","position":1,"cik":"0001866239","reported_name":"Siemers Eric","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Medical Officer"}}],"security":"Common Stock","published_at":"2026-01-21T18:31:11.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":99133,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":258597,"source":{"system":"sec-edgar","filing":"0001628280-26-002959","document":"wk-form4_1769038268.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1866239/000162828026002959/wk-form4_1769038268.xml","form_type":"4"}},{"id":934436,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69068,"kind":"person","name":"Schacterle Amy","position":1,"cik":"0002042021","reported_name":"Schacterle Amy","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Regulatory Officer"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T18:29:51.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":126900,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":126900,"derivative":{"exercise_price":1.89,"expiration_date":"2036-01-16","underlying":"Common Stock","underlying_shares":126900},"source":{"system":"sec-edgar","filing":"0001628280-26-002957","document":"wk-form4_1769038189.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/2042021/000162828026002957/wk-form4_1769038189.xml","form_type":"4"}},{"id":934435,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69068,"kind":"person","name":"Schacterle Amy","position":1,"cik":"0002042021","reported_name":"Schacterle Amy","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Regulatory Officer"}}],"security":"Common Stock","published_at":"2026-01-21T18:29:51.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":84600,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":92303,"source":{"system":"sec-edgar","filing":"0001628280-26-002957","document":"wk-form4_1769038189.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2042021/000162828026002957/wk-form4_1769038189.xml","form_type":"4"}},{"id":934411,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69062,"kind":"person","name":"Doherty James J.","position":1,"cik":"0002009718","reported_name":"Doherty James J.","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"President and CDO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2026-01-21T18:29:25.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":250300,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in 48 equal monthly installments such that the option is fully vested on the fourth anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":250300,"derivative":{"exercise_price":1.89,"expiration_date":"2036-01-16","underlying":"Common Stock","underlying_shares":250300},"source":{"system":"sec-edgar","filing":"0001628280-26-002956","document":"wk-form4_1769038162.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/2009718/000162828026002956/wk-form4_1769038162.xml","form_type":"4"}},{"id":934410,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69062,"kind":"person","name":"Doherty James J.","position":1,"cik":"0002009718","reported_name":"Doherty James J.","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"President and CDO"}}],"security":"Common Stock","published_at":"2026-01-21T18:29:25.000Z","date":"2026-01-16","kind":"grant","planned":false,"acquired":true,"shares":166867,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in three equal annual installments commencing one year after the grant date, subject to the Reporting Person's continuous service through each such vesting date."}],"balance_after":220900,"source":{"system":"sec-edgar","filing":"0001628280-26-002956","document":"wk-form4_1769038162.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2009718/000162828026002956/wk-form4_1769038162.xml","form_type":"4"}},{"id":940760,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-12T23:52:52.000Z","date":"2026-01-08","kind":"sale","planned":false,"acquired":false,"shares":6888,"price":1.8166,"value":12512.7408,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7200 to $1.9500. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":209951,"source":{"system":"sec-edgar","filing":"0001628280-26-001898","document":"wk-form4_1768261959.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001898/wk-form4_1768261959.xml","form_type":"4"}},{"id":940759,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-12T23:52:20.000Z","date":"2026-01-08","kind":"sale","planned":false,"acquired":false,"shares":3530,"price":1.8588,"value":6561.564,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 25, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.8000 to $1.9500. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":123269,"source":{"system":"sec-edgar","filing":"0001628280-26-001897","document":"wk-form4_1768261937.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001897/wk-form4_1768261937.xml","form_type":"4"}},{"id":941063,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-12T18:51:10.000Z","date":"2026-01-12","kind":"sale","planned":false,"acquired":false,"shares":8548,"price":1.7148,"value":14658.1104,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.6700 to $1.8400. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":83800,"source":{"system":"sec-edgar","filing":"0001628280-26-001896","document":"wk-form4_1768261867.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001896/wk-form4_1768261867.xml","form_type":"4"}},{"id":941062,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-12T18:51:10.000Z","date":"2026-01-09","kind":"sale","planned":false,"acquired":false,"shares":5200,"price":1.7633,"value":9169.16,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7100 to $1.8150. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":92348,"source":{"system":"sec-edgar","filing":"0001628280-26-001896","document":"wk-form4_1768261867.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001896/wk-form4_1768261867.xml","form_type":"4"}},{"id":941061,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-12T18:51:10.000Z","date":"2026-01-08","kind":"sale","planned":false,"acquired":false,"shares":30092,"price":1.8233,"value":54866.7436,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7200 to $1.9500. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":97548,"source":{"system":"sec-edgar","filing":"0001628280-26-001896","document":"wk-form4_1768261867.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001896/wk-form4_1768261867.xml","form_type":"4"}},{"id":941060,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-12T18:51:10.000Z","date":"2026-01-08","kind":"sale","planned":false,"acquired":false,"shares":6819,"price":1.8154,"value":12379.2126,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7200 to $1.9500. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":127640,"source":{"system":"sec-edgar","filing":"0001628280-26-001896","document":"wk-form4_1768261867.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001896/wk-form4_1768261867.xml","form_type":"4"}},{"id":941129,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-12T18:50:33.000Z","date":"2026-01-12","kind":"sale","planned":false,"acquired":false,"shares":5388,"price":1.7273,"value":9306.6924,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 27, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.6700 to $1.8400. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":593510,"source":{"system":"sec-edgar","filing":"0001628280-26-001895","document":"wk-form4_1768261820.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026001895/wk-form4_1768261820.xml","form_type":"4"}},{"id":941128,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-12T18:50:33.000Z","date":"2026-01-09","kind":"sale","planned":false,"acquired":false,"shares":12941,"price":1.7643,"value":22831.8063,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 27, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7100 to $1.8100. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":598898,"source":{"system":"sec-edgar","filing":"0001628280-26-001895","document":"wk-form4_1768261820.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026001895/wk-form4_1768261820.xml","form_type":"4"}},{"id":941127,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-12T18:50:33.000Z","date":"2026-01-08","kind":"sale","planned":false,"acquired":false,"shares":8143,"price":1.8194,"value":14815.3742,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 27, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7200 to $1.8700. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":611839,"source":{"system":"sec-edgar","filing":"0001628280-26-001895","document":"wk-form4_1768261820.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026001895/wk-form4_1768261820.xml","form_type":"4"}},{"id":942399,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69062,"kind":"person","name":"Doherty James J.","position":1,"cik":"0002009718","reported_name":"Doherty James J.","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"President and CDO"}}],"security":"Common Stock","published_at":"2026-01-09T16:39:25.000Z","date":"2026-01-08","kind":"sale","planned":false,"acquired":false,"shares":6467,"price":1.8198,"value":11768.6466,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 30, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.7200 to $1.9500. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":54033,"source":{"system":"sec-edgar","filing":"0001628280-26-001636","document":"wk-form4_1767994762.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/2009718/000162828026001636/wk-form4_1767994762.xml","form_type":"4"}},{"id":942398,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69062,"kind":"person","name":"Doherty James J.","position":1,"cik":"0002009718","reported_name":"Doherty James J.","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"President and CDO"}}],"security":"Common Stock","published_at":"2026-01-09T16:39:25.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":1700,"price":1.9879,"value":3379.43,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 30, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9550 to $2.0200. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Number of securities reported as beneficially owned by Mr. Doherty following the reported transaction reflects the correction of a typographical error in the Form 4 report filed January 7, 2025, which overreported the number of RSUs granted to Mr. Doherty on January 6, 2025, by 400 shares."}],"balance_after":60500,"source":{"system":"sec-edgar","filing":"0001628280-26-001636","document":"wk-form4_1767994762.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2009718/000162828026001636/wk-form4_1767994762.xml","form_type":"4"}},{"id":942464,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":69068,"kind":"person","name":"Schacterle Amy","position":1,"cik":"0002042021","reported_name":"Schacterle Amy","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Regulatory Officer"}}],"security":"Common Stock","published_at":"2026-01-09T16:38:43.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":1097,"price":1.9838,"value":2176.2286,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 30, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9550 to $2.0100. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":7703,"source":{"system":"sec-edgar","filing":"0001628280-26-001633","document":"wk-form4_1767994720.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2042021/000162828026001633/wk-form4_1767994720.xml","form_type":"4"}},{"id":944016,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:31:50.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":1700,"price":1.9862,"value":3376.54,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F5","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of RSUs pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F6","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9600 to $2.0100. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":216839,"source":{"system":"sec-edgar","filing":"0001628280-26-001265","document":"wk-form4_1767839507.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001265/wk-form4_1767839507.xml","form_type":"4"}},{"id":944015,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:31:50.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":4105,"price":1.995,"value":8189.475,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9500 to $2.0400. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":218539,"source":{"system":"sec-edgar","filing":"0001628280-26-001265","document":"wk-form4_1767839507.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001265/wk-form4_1767839507.xml","form_type":"4"}},{"id":944014,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:31:50.000Z","date":"2026-01-06","kind":"sale","planned":false,"acquired":false,"shares":5100,"price":1.9662,"value":10027.62,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9400 to $1.9900. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":222644,"source":{"system":"sec-edgar","filing":"0001628280-26-001265","document":"wk-form4_1767839507.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001265/wk-form4_1767839507.xml","form_type":"4"}},{"id":944013,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68870,"kind":"person","name":"Zuga Matt","position":1,"cik":"0001790214","reported_name":"Zuga Matt","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Chief Business Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:31:50.000Z","date":"2026-01-05","kind":"sale","planned":false,"acquired":false,"shares":4000,"price":1.9606,"value":7842.4,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9100 to $1.9750. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":227744,"source":{"system":"sec-edgar","filing":"0001628280-26-001265","document":"wk-form4_1767839507.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001265/wk-form4_1767839507.xml","form_type":"4"}},{"id":944001,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:30:15.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":1700,"price":1.9871,"value":3378.07,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F4","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of RSUs pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 25, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9550 to $2.0200. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":126799,"source":{"system":"sec-edgar","filing":"0001628280-26-001261","document":"wk-form4_1767839412.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001261/wk-form4_1767839412.xml","form_type":"4"}},{"id":944000,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:30:15.000Z","date":"2026-01-06","kind":"sale","planned":false,"acquired":false,"shares":3618,"price":1.9664,"value":7114.4352,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9400 to $1.9900. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":128499,"source":{"system":"sec-edgar","filing":"0001628280-26-001261","document":"wk-form4_1767839412.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001261/wk-form4_1767839412.xml","form_type":"4"}},{"id":943999,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68869,"kind":"person","name":"Barton Russell","position":1,"cik":"0001867418","reported_name":"Barton Russell","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2026-01-08T02:30:15.000Z","date":"2026-01-05","kind":"sale","planned":false,"acquired":false,"shares":4000,"price":1.9581,"value":7832.4,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 30, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9100 to $1.9800. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":132117,"source":{"system":"sec-edgar","filing":"0001628280-26-001261","document":"wk-form4_1767839412.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000162828026001261/wk-form4_1767839412.xml","form_type":"4"}},{"id":944727,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68913,"kind":"person","name":"Siemers Eric","position":1,"cik":"0001866239","reported_name":"Siemers Eric","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Medical Officer"}}],"security":"Common Stock","published_at":"2026-01-07T21:31:31.000Z","date":"2026-01-06","kind":"sale","planned":false,"acquired":false,"shares":6834,"price":1.967,"value":13442.478,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 3, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9400 to $1.9900. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":159464,"source":{"system":"sec-edgar","filing":"0001628280-26-001264","document":"wk-form4_1767839485.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1866239/000162828026001264/wk-form4_1767839485.xml","form_type":"4"}},{"id":944726,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68913,"kind":"person","name":"Siemers Eric","position":1,"cik":"0001866239","reported_name":"Siemers Eric","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Medical Officer"}}],"security":"Common Stock","published_at":"2026-01-07T21:31:31.000Z","date":"2026-01-05","kind":"sale","planned":false,"acquired":false,"shares":4000,"price":1.9587,"value":7834.8,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 3, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9100 to $1.9750. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":166298,"source":{"system":"sec-edgar","filing":"0001628280-26-001264","document":"wk-form4_1767839485.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1866239/000162828026001264/wk-form4_1767839485.xml","form_type":"4"}},{"id":944725,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-07T21:31:07.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":37755,"price":1.986,"value":74981.43,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9500 to $2.0300. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":619982,"source":{"system":"sec-edgar","filing":"0001628280-26-001263","document":"wk-form4_1767839464.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026001263/wk-form4_1767839464.xml","form_type":"4"}},{"id":944724,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-07T21:31:07.000Z","date":"2026-01-06","kind":"sale","planned":false,"acquired":false,"shares":5102,"price":1.9662,"value":10031.5524,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9400 to $2.0000. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":657737,"source":{"system":"sec-edgar","filing":"0001628280-26-001263","document":"wk-form4_1767839464.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026001263/wk-form4_1767839464.xml","form_type":"4"}},{"id":944723,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":68912,"kind":"person","name":"OConnell Daniel Joseph","position":1,"cik":"0001865136","reported_name":"OConnell Daniel Joseph","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-07T21:31:07.000Z","date":"2026-01-05","kind":"sale","planned":false,"acquired":false,"shares":4649,"price":1.971,"value":9163.179,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9000 to $2.0600. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":662839,"source":{"system":"sec-edgar","filing":"0001628280-26-001263","document":"wk-form4_1767839464.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1865136/000162828026001263/wk-form4_1767839464.xml","form_type":"4"}},{"id":944562,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-07T21:30:43.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":10070,"price":1.9896,"value":20035.272,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F4","text":"Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9500 to $2.0250. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":134459,"source":{"system":"sec-edgar","filing":"0001628280-26-001262","document":"wk-form4_1767839440.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001262/wk-form4_1767839440.xml","form_type":"4"}},{"id":944561,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-07T21:30:43.000Z","date":"2026-01-07","kind":"sale","planned":false,"acquired":false,"shares":1700,"price":1.9876,"value":3378.92,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F5","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of RSUs pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F6","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9600 to $2.0200. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":144529,"source":{"system":"sec-edgar","filing":"0001628280-26-001262","document":"wk-form4_1767839440.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001262/wk-form4_1767839440.xml","form_type":"4"}},{"id":944560,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-07T21:30:43.000Z","date":"2026-01-06","kind":"sale","planned":false,"acquired":false,"shares":3801,"price":1.967,"value":7476.567,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F4","text":"Represents the number of shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 29, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9400 to $2.0000. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":146229,"source":{"system":"sec-edgar","filing":"0001628280-26-001262","document":"wk-form4_1767839440.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001262/wk-form4_1767839440.xml","form_type":"4"}},{"id":944559,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-07T21:30:43.000Z","date":"2026-01-06","kind":"sale","planned":false,"acquired":false,"shares":7097,"price":1.9672,"value":13961.2184,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 15, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9400 to $2.0000. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":150030,"source":{"system":"sec-edgar","filing":"0001628280-26-001262","document":"wk-form4_1767839440.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001262/wk-form4_1767839440.xml","form_type":"4"}},{"id":944558,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":61758,"kind":"person","name":"Meisner Derek M","position":1,"cik":"0001752461","reported_name":"Meisner Derek M","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer & Corp Sec"}}],"security":"Common Stock","published_at":"2026-01-07T21:30:43.000Z","date":"2026-01-05","kind":"sale","planned":false,"acquired":false,"shares":4000,"price":1.9595,"value":7838.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the number of shares sold by the Reporting Person through an automatic \"sell to cover\" transaction to satisfy tax withholding obligations in connection with the vesting of restricted stock units (\"RSUs\") pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 15, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $1.9200 to $1.9750. Upon request, the Reporting Person will provide to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":157127,"source":{"system":"sec-edgar","filing":"0001628280-26-001262","document":"wk-form4_1767839440.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1752461/000162828026001262/wk-form4_1767839440.xml","form_type":"4"}},{"id":1003438,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40806,"kind":"person","name":"Golumbeski George","position":1,"cik":"0001586660","reported_name":"Golumbeski George","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2025-11-10T21:49:06.000Z","date":"2025-11-06","kind":"grant","planned":false,"acquired":true,"shares":50000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The shares subject to the option will vest in equal monthly installments over a three-year period such that the option is fully vested on the third anniversary of the date of grant, subject to the Reporting Person's continuous service through each such vesting date and shall vest and become immediately exercisable prior to the effectiveness of a change in control."}],"balance_after":50000,"derivative":{"exercise_price":1.9,"expiration_date":"2035-11-06","underlying":"Common Stock","underlying_shares":50000},"source":{"system":"sec-edgar","filing":"0001586660-25-000003","document":"wk-form4_1762811342.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000158666025000003/wk-form4_1762811342.xml","form_type":"4"}},{"id":1121026,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":19524,"kind":"organization","name":"RA CAPITAL MANAGEMENT, L.P.","position":1,"cik":"0001346824","reported_name":"RA CAPITAL MANAGEMENT, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19525,"kind":"organization","name":"RA Capital Healthcare Fund LP","position":2,"cik":"0001315082","reported_name":"RA Capital Healthcare Fund LP","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":29189,"kind":"person","name":"RA Capital Nexus Fund II, L.P.","position":3,"cik":"0001825376","reported_name":"RA Capital Nexus Fund II, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":19526,"kind":"person","name":"Kolchinsky Peter","position":4,"cik":"0001384859","reported_name":"Kolchinsky Peter","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19527,"kind":"person","name":"Shah Rajeev M.","position":5,"cik":"0001619841","reported_name":"Shah Rajeev M.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-05T22:12:53.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":19500,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See Footnotes"},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"Represents the grant of an option to Dr. Stoppel pursuant to the Issuer's non-employee director compensation policy. The shares subject to the option will vest on the earlier of June 4, 2026 or the 2026 annual stockholder meeting, subject to Dr. Stoppel's continuous service as a director through such vesting date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"RA Capital Management, L.P. (the \"Adviser\") is the investment manager for RA Capital Healthcare Fund, L.P. (the \"Fund\"), RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The general partner of the Adviser is RA Capital Management GP, LLC (the\n\"Adviser GP\"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Under Dr. Stoppel's arrangement with the Adviser, Dr. Stoppel holds the RSU and the option for the benefit of the Fund and the Nexus Fund II. Dr. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSU, as applicable, which will offset advisory fees owed by the Fund and the Nexus Fund II to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the RSU, the option and underlying common stock."}],"balance_after":19500,"derivative":{"exercise_price":1.07,"expiration_date":"2035-06-04","underlying":"Common Stock","underlying_shares":19500},"source":{"system":"sec-edgar","filing":"0001415889-25-015836","document":"form4-06052025_100655.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1315082/000141588925015836/form4-06052025_100655.xml","form_type":"4"}},{"id":1121025,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":19524,"kind":"organization","name":"RA CAPITAL MANAGEMENT, L.P.","position":1,"cik":"0001346824","reported_name":"RA CAPITAL MANAGEMENT, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19525,"kind":"organization","name":"RA Capital Healthcare Fund LP","position":2,"cik":"0001315082","reported_name":"RA Capital Healthcare Fund LP","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":29189,"kind":"person","name":"RA Capital Nexus Fund II, L.P.","position":3,"cik":"0001825376","reported_name":"RA Capital Nexus Fund II, L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":19526,"kind":"person","name":"Kolchinsky Peter","position":4,"cik":"0001384859","reported_name":"Kolchinsky Peter","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}},{"id":19527,"kind":"person","name":"Shah Rajeev M.","position":5,"cik":"0001619841","reported_name":"Shah Rajeev M.","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2025-06-05T22:12:53.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":12800,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents the grant of a restricted stock unit (\"RSU\") award to Laura Stoppel pursuant to the Issuer's non-employee director compensation policy. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of June 4, 2026 or the Issuer's 2026 annual stockholder meeting, subject to Dr. Stoppel's continuous service as a director through such vesting date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"RA Capital Management, L.P. (the \"Adviser\") is the investment manager for RA Capital Healthcare Fund, L.P. (the \"Fund\"), RA Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The general partner of the Adviser is RA Capital Management GP, LLC (the\n\"Adviser GP\"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Under Dr. Stoppel's arrangement with the Adviser, Dr. Stoppel holds the RSU and the option for the benefit of the Fund and the Nexus Fund II. Dr. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSU, as applicable, which will offset advisory fees owed by the Fund and the Nexus Fund II to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the RSU, the option and underlying common stock."}],"balance_after":12800,"source":{"system":"sec-edgar","filing":"0001415889-25-015836","document":"form4-06052025_100655.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1315082/000141588925015836/form4-06052025_100655.xml","form_type":"4"}},{"id":1121508,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40979,"kind":"person","name":"Stoppel Laura","position":1,"cik":"0001865119","reported_name":"Stoppel Laura","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2025-06-05T22:05:34.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":19500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2026 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"Under the Reporting Person's arrangement with RA Capital Management, L.P. (the \"Adviser\"), the Reporting Person holds the option and RSUs for the benefit of the R.A. Capital Healthcare Fund, L.P. (the \"Fund\"), R.A. Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement, as applicable, which will offset advisory fees owed by the Fund, Nexus Fund II and the Account to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the option and RSUs and underlying common stock."}],"balance_after":19500,"derivative":{"exercise_price":1.07,"expiration_date":"2035-06-04","underlying":"Common Stock","underlying_shares":19500},"source":{"system":"sec-edgar","filing":"0001576885-25-000084","document":"wk-form4_1749160924.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1865119/000157688525000084/wk-form4_1749160924.xml","form_type":"4"}},{"id":1121507,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40979,"kind":"person","name":"Stoppel Laura","position":1,"cik":"0001865119","reported_name":"Stoppel Laura","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-06-05T22:05:34.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":12800,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2026 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"Under the Reporting Person's arrangement with RA Capital Management, L.P. (the \"Adviser\"), the Reporting Person holds the option and RSUs for the benefit of the R.A. Capital Healthcare Fund, L.P. (the \"Fund\"), R.A. Capital Nexus Fund II, L.P. (the \"Nexus Fund II\") and a separately managed account (the \"Account\"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement, as applicable, which will offset advisory fees owed by the Fund, Nexus Fund II and the Account to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the option and RSUs and underlying common stock."}],"balance_after":12800,"source":{"system":"sec-edgar","filing":"0001576885-25-000084","document":"wk-form4_1749160924.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1865119/000157688525000084/wk-form4_1749160924.xml","form_type":"4"}},{"id":1120919,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40808,"kind":"person","name":"Stalfort John A III","position":1,"cik":"0001709418","reported_name":"Stalfort John A III","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2025-06-05T20:59:03.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":19500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2026 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":19500,"derivative":{"exercise_price":1.07,"expiration_date":"2035-06-04","underlying":"Common Stock","underlying_shares":19500},"source":{"system":"sec-edgar","filing":"0001576885-25-000082","document":"wk-form4_1749157011.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000157688525000082/wk-form4_1749157011.xml","form_type":"4"}},{"id":1120918,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":40808,"kind":"person","name":"Stalfort John A III","position":1,"cik":"0001709418","reported_name":"Stalfort John A III","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-06-05T20:59:03.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":12800,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2026 annual\nstockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":185124,"source":{"system":"sec-edgar","filing":"0001576885-25-000082","document":"wk-form4_1749157011.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1576885/000157688525000082/wk-form4_1749157011.xml","form_type":"4"}},{"id":1121520,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":39704,"kind":"person","name":"Fountain Nathan B","position":1,"cik":"0001869596","reported_name":"Fountain Nathan B","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (right to buy)","published_at":"2025-06-05T20:57:56.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":19500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares subject to the option will vest in full on the earlier of the first anniversary of the date of grant or the 2026 annual stockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":19500,"derivative":{"exercise_price":1.07,"expiration_date":"2035-06-04","underlying":"Common Stock","underlying_shares":19500},"source":{"system":"sec-edgar","filing":"0001576885-25-000080","document":"wk-form4_1749156801.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1869596/000157688525000080/wk-form4_1749156801.xml","form_type":"4"}},{"id":1121519,"issuer":{"id":6281,"kind":"organization","name":"Acumen Pharmaceuticals, Inc."},"owners":[{"id":39704,"kind":"person","name":"Fountain Nathan B","position":1,"cik":"0001869596","reported_name":"Fountain Nathan B","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-06-05T20:57:56.000Z","date":"2025-06-04","kind":"grant","planned":false,"acquired":true,"shares":12800,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents a restricted stock unit (\"RSU\") award. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of the first anniversary of the date of grant or the 2026 annual\nstockholder meeting, subject to the Reporting Person's continuous service through such vesting date."}],"balance_after":19050,"source":{"system":"sec-edgar","filing":"0001576885-25-000080","document":"wk-form4_1749156801.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1869596/000157688525000080/wk-form4_1749156801.xml","form_type":"4"}}],"next_cursor":"2025-06-05T20:57:56.000000Z,1121519"}