Acumen Pharmaceuticals's top three insider shareholders as of April 28, 2026 are Robert D. Hardie (TenPercentOwner, 3.86Mn shares), Capital Ventures Discovery Fund Iii, L.P. Sands (TenPercentOwner, 3.42Mn shares), Daniel Joseph Oconnell (Chief Executive Officer, 881.27K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Robert D. Hardie | - | 0 | 3,859,141 | 08 Jul, 2021 |
| Capital Ventures Discovery Fund Iii, L.P. Sands | - | 3,417,075 | 0 | 08 Jul, 2021 |
| Daniel Joseph Oconnell | Chief Executive Officer | 881,275 | 0 | 23 Jan, 2026 |
| Matt Zuga | Cfo Chief Business Officer | 304,924 | 0 | 23 Jan, 2026 |
| Eric Siemers | Chief Medical Officer | 255,371 | 0 | 23 Jan, 2026 |
| James J. Doherty | President And Cdo | 220,900 | 0 | 21 Jan, 2026 |
| Russell Barton | Chief Operating Officer | 205,092 | 0 | 23 Jan, 2026 |
| Amy Schacterle | Chief Regulatory Officer | 92,303 | 0 | 21 Jan, 2026 |
| Nathan B Fountain | - | 19,050 | 0 | 05 Jun, 2025 |
| Derrell Porter | - | 12,800 | 0 | 05 Jun, 2025 |
| Laura Stoppel | - | 12,800 | 0 | 05 Jun, 2025 |
| Jeffrey L. Ives | - | 12,800 | 0 | 05 Jun, 2025 |
| Kimberlee C Drapkin | - | 12,800 | 0 | 05 Jun, 2025 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 21 Jan, 2026 | Eric Siemers | Common Stock | D | 2,331 | $1.80 | 256,266 | D | S |
| 21 Jan, 2026 | Matt Zuga | Common Stock | D | 2,473 | $1.81 | 306,611 | D | S |
| 21 Jan, 2026 | Daniel Joseph Oconnell | Common Stock | D | 9,346 | $1.81 | 883,964 | D | S |
| 21 Jan, 2026 | Russell Barton | Common Stock | D | 2,315 | $1.81 | 205,554 | D | S |
| 22 Jan, 2026 | Eric Siemers | Common Stock | D | 895 | $1.82 | 255,371 | D | S |
| 22 Jan, 2026 | Russell Barton | Common Stock | D | 462 | $1.84 | 205,092 | D | S |
| 22 Jan, 2026 | Matt Zuga | Common Stock | D | 1,687 | $1.86 | 304,924 | D | S |
| 22 Jan, 2026 | Daniel Joseph Oconnell | Common Stock | D | 2,689 | $1.88 | 881,275 | D | S |
| 16 Jan, 2026 | Eric Siemers | Common Stock | A | 99,133 | $0.00 | 258,597 | D | A |
| 16 Jan, 2026 | Amy Schacterle | Common Stock | A | 84,600 | $0.00 | 92,303 | D | A |
| 16 Jan, 2026 | Russell Barton | Common Stock | A | 84,600 | $0.00 | 207,869 | D | A |
| 16 Jan, 2026 | Matt Zuga | Common Stock | A | 99,133 | $0.00 | 309,084 | D | A |
| 16 Jan, 2026 | James J. Doherty | Common Stock | A | 166,867 | $0.00 | 220,900 | D | A |
| 20 Jan, 2026 | Daniel Joseph Oconnell | Common Stock | A | 299,800 | $0.00 | 893,310 | D | A |
| 16 Jan, 2026 | Eric Siemers | Employee Stock Option (right to buy) | A | 148,700 | $0.00 | 148,700 | D | A |
| 16 Jan, 2026 | James J. Doherty | Employee Stock Option (right to buy) | A | 250,300 | $0.00 | 250,300 | D | A |
| 16 Jan, 2026 | Amy Schacterle | Employee Stock Option (right to buy) | A | 126,900 | $0.00 | 126,900 | D | A |
| 20 Jan, 2026 | Daniel Joseph Oconnell | Employee Stock Option (right to buy) | A | 450,000 | $0.00 | 450,000 | D | A |
| 16 Jan, 2026 | Russell Barton | Employee Stock Option (right to buy) | A | 126,900 | $0.00 | 126,900 | D | A |
| 16 Jan, 2026 | Matt Zuga | Employee Stock Option (right to buy) | A | 148,700 | $0.00 | 148,700 | D | A |