Acumen Pharmaceuticals, Inc.
ABOS- Exchange
- Nasdaq
- Industry
- Biological Products, (No Diagnostic Substances)
- SEC CIK
- 0001576885
No open-market purchases or sales by Acumen Pharmaceuticals, Inc. insiders were filed in the last 90 days; 96 institutions reported holding it in 13F filings for Q2 2026, worth $127.8M in total; no superinvestor holds it.
Holders of 5% or more of ABOS
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Acumen Pharmaceuticals, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Ra Capital Management, L.P. | 13D/A | 29.50%21.1M shares | +4.70 ppfrom 24.80% | Jul 16, 20215 filings | Mar 17, 2026 | SEC |
| Sands Capital Ventures, LLC | 13G/A | 5.60%3.42M shares | – | Feb 14, 20232 filings | Aug 13, 2025 | SEC |
| Murray James B Jr | 13G | 5.00%3.61M shares | – | Feb 14, 20223 filings | Apr 7, 2026 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
21 Schedule 13D and 13G filings on Acumen Pharmaceuticals, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Apr 7, 20264:05 PM ET | Murray James B Jr | 13G | 5.00%3.61M shares | – | Apr 4, 2025 | SEC |
| Mar 17, 20264:33 PM ET | Ra Capital Management, L.P.and 3 others | 13D/A | 29.50%21.1M shares | +4.70 ppfrom 24.80% | Mar 13, 2026 | SEC |
| Nov 4, 202511:25 AM ET | Franklin Resources Incand 2 others | 13G/A | 3.80%2.31M shares | –Below 5% | Sep 30, 2025 | SEC |
| Aug 13, 202511:27 AM ET | Sands Capital Ventures, LLCand 4 others | 13G/A | 5.60%3.42M shares | – | Jun 30, 2025 | SEC |
| Mar 31, 20254:57 PM ET | Ra Capital Management, L.P.and 3 others | 13D/A | 24.80%15.0M shares | – | Mar 27, 2025 | SEC |
| Feb 14, 2024 | Deep Track Capital, LP | 13G/AOld format | – | – | – | SEC |
| Feb 6, 2024 | Franklin Resources Inc | 13GOld format | – | New | – | SEC |
| Jan 24, 2024 | Murray James B Jr | 13G/AOld format | – | – | – | SEC |
| Jul 25, 2023 | Ra Capital Management, L.P. | 13D/AOld format | – | – | – | SEC |
| Feb 14, 2023 | Manning Paul B | 13G/AOld format | – | – | – | SEC |
| Feb 14, 2023 | Sands Capital Ventures, LLC | 13G/AOld format | – | – | – | SEC |
| Feb 14, 2023 | Deep Track Capital, LP | 13G/AOld format | – | – | – | SEC |
| Oct 7, 20222:58 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 16, 2022 | Hardie Molly G. | 13GOld format | – | New | – | SEC |
| Feb 15, 2022 | Manning Paul B | 13GOld format | – | New | – | SEC |
| Feb 14, 2022 | Murray James B Jr | 13GOld format | – | New | – | SEC |
| Feb 4, 20224:12 PM ET | BlackRock Inc. | 13GOld format | – | New | – | SEC |
| Jan 27, 2022 | Deep Track Capital, LP | 13GOld format | – | New | – | SEC |
| Sep 13, 2021 | Ra Capital Management, L.P. | 13D/AOld format | – | – | – | SEC |
| Jul 16, 2021 | Ra Capital Management, L.P. | 13DOld format | – | New | – | SEC |
| Jul 13, 2021 | Sands Capital Ventures Discovery Fund III, L.P. | 13GOld format | – | New | – | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Acumen Pharmaceuticals, Inc. shares.
No Form 144 notices for Acumen Pharmaceuticals, Inc. are on file.