Key facts
- ABOS - Acumen Pharmaceuticals, Inc. has 19 insiders with reported activity on this page.
- Net insider value flow over the last year: -$535,919.
- Recent transaction rows are available for direct filing-level review.
Insider Transactions Reported by 19 Insiders of Acumen Pharmaceuticals, Inc.
- Symbol
- ABOS on Nasdaq
- Location
- Newton, MA
Change
- Buy value: ; sell value: $535,918.
- Net share flow: -266,428.
Research use
- This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
- Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.
Evidence
Filed on Form 4
See Original Filing
Issuer insider activity is sourced from SEC Forms 3, 4, and 5.
Insider trading overview
Last 12 monthsNet insider flow leans to selling over the last 12 months. Net value: -$535,919.
Buys
$0
Shares: 0
Insiders: 0
Sells
$535,919
Shares: 266,428
Insiders: 7
Net
-$535,919
Shares: -266,428
Insiders: -7
| Window (months) | Buy shares | Sell shares | Buy $ | Sell $ | Net $ |
|---|---|---|---|---|---|
| 0-3 | 0 | 11,496 | $0 | $35,125 | -$35,125 |
| 3-6 | 0 | 254,932 | $0 | $500,794 | -$500,794 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Acumen Pharmaceuticals, Inc. executives and other stock owners filed with the SEC include:
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | Director, 10%+ Owner | $49,860,878 | Mixed | 16 Mar 2026 | ||
| Sands Capital Ventures Discovery Fund III, L.P. | 10%+ Owner | $11,859,300 | Mixed | 06 Jul 2021 | ||
| Paul B. Manning | 10%+ Owner | $2,283,603 | Mixed | 06 Jul 2021 | ||
| Robert D. Hardie | 10%+ Owner | $2,283,603 | Mixed | 06 Jul 2021 | ||
| Daniel Joseph OConnell | Chief Executive Officer, Director | $1,660,145 | -$163,123 | -8.9% | Filing P/S | 21 Jan 2026 |
| Derek M. Meisner | Chief Legal Officer & Corp Sec | $567,236 | -$248,888 | -30% | Filing P/S | 06 Mar 2026 |
| Matt Zuga | CFO & Chief Business Officer | $567,158 | -$49,556 | -8% | Filing P/S | 21 Jan 2026 |
| James J. Doherty | President and CDO | $466,054 | -$15,148 | -3.1% | Mixed | 16 Jan 2026 |
| Eric Siemers | Chief Medical Officer | $464,775 | -$27,110 | -5.5% | Filing P/S | 21 Jan 2026 |
| Russell Barton | Chief Operating Officer | $377,369 | -$29,917 | -7.3% | Filing P/S | 21 Jan 2026 |
| John A. Stalfort III | Director | $203,636 | Mixed | 04 Jun 2025 | ||
| Amy Schacterle | Chief Regulatory Officer | $194,740 | -$2,176 | -1.1% | Mixed | 16 Jan 2026 |
| Nathan B. Fountain | Director | $20,955 | Mixed | 04 Jun 2025 | ||
| Laura Stoppel | Director | $14,080 | Mixed | 04 Jun 2025 | ||
| Kimberlee C. Drapkin | Director | $14,080 | Mixed | 04 Jun 2025 | ||
| Derrell Porter | Director | $14,080 | Mixed | 04 Jun 2025 | ||
| Jeffrey L. Ives | Director | $14,080 | Mixed | 04 Jun 2025 | ||
| George Golumbeski | Director | Mixed | 06 Nov 2025 | |||
| Jeffrey Sevigny | Director | Mixed | 15 Jun 2022 |
Top shareholders of Acumen Pharmaceuticals, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.
Methodology: rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
| Holder | Source | Role / Reporting | Ownership % | Shares | Holdings Value | 12M Net Δ | As of | Details |
|---|---|---|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. |
13D/G
3/4/5
13F
|
Director, 10%+ Owner · Company |
30%
|
21,101,669
|
$55,075,356 | +$15,883,432 | 13 Mar 2026 | |
| Sands Capital Alternatives, LLC |
13F
13D/G
|
Company |
5.6%
from 13D/G
|
3,720,105
|
$8,779,448 | — | 31 Mar 2026 | |
| James B. Murray Jr. |
13D/G
|
— |
5%
|
3,611,360
|
$9,425,650 | $0 | 04 Apr 2025 | |
| FRANKLIN RESOURCES INC |
13F
13D/G
|
Company |
3.8%
from 13D/G
|
2,305,096
|
$5,440,027 | — | 31 Mar 2026 | |
| Alyeska Investment Group, L.P. |
13F
|
Company |
3.4%
|
2,454,754
|
$5,776,765 | — | 31 Mar 2026 | |
| ADAR1 Capital Management, LLC |
13F
|
Company |
3%
|
2,156,334
|
$5,088,948 | — | 31 Mar 2026 | |
| Knollwood Investment Advisory, LLC |
13F
|
Company |
2.3%
|
1,628,510
|
$3,843,284 | — | 31 Mar 2026 | |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
|
Company |
2.1%
|
1,506,277
|
$3,554,814 | — | 31 Mar 2026 | |
| FMR LLC |
13F
|
Company |
1.6%
|
1,157,346
|
$2,731,337 | — | 31 Mar 2026 | |
| Ikarian Capital, LLC |
13F
|
Company |
1.5%
|
1,053,797
|
$2,486,960 | — | 31 Mar 2026 | |
| Hudson Bay Capital Management LP |
13F
|
Company |
1.3%
|
968,940
|
$2,286,698 | — | 31 Mar 2026 | |
| Pathstone Holdings, LLC |
13F
|
Company |
1.2%
|
859,110
|
$2,027,500 | — | 31 Mar 2026 | |
| SG Americas Securities, LLC |
13F
|
Company |
1%
|
719,257
|
$1,697,000 | — | 31 Mar 2026 | |
| MILLENNIUM MANAGEMENT LLC |
13F
|
Company |
0.91%
|
659,675
|
$1,556,833 | — | 31 Mar 2026 | |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP |
13F
|
Company |
0.83%
|
601,476
|
$1,419,483 | — | 31 Mar 2026 | |
| TWO SIGMA INVESTMENTS, LP |
13F
|
Company |
0.73%
|
530,812
|
$1,252,716 | — | 31 Mar 2026 | |
| Laurion Capital Management LP |
13F
|
Company |
0.73%
|
525,444
|
$1,240,048 | — | 31 Mar 2026 | |
| RENAISSANCE TECHNOLOGIES LLC |
13F
|
Company |
0.66%
|
473,946
|
$1,118,513 | — | 31 Mar 2026 | |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
|
Company |
0.58%
|
416,238
|
$982,755 | — | 31 Mar 2026 | |
| BANK OF AMERICA CORP /DE/ |
13F
|
Company |
0.44%
|
320,216
|
$755,710 | — | 31 Mar 2026 | |
| BOOTHBAY FUND MANAGEMENT, LLC |
13F
|
Company |
0.38%
|
273,012
|
$644,308 | — | 31 Mar 2026 | |
| GOLDMAN SACHS GROUP INC |
13F
|
Company |
0.29%
|
206,683
|
$487,772 | — | 31 Mar 2026 | |
| VANGUARD FIDUCIARY TRUST CO |
13F
|
Company |
0.28%
|
199,226
|
$470,173 | — | 31 Mar 2026 | |
| MARSHALL WACE, LLP |
13F
|
Company |
0.27%
|
192,889
|
$455,218 | — | 31 Mar 2026 | |
| ACADIAN ASSET MANAGEMENT LLC |
13F
|
Company |
0.26%
|
185,850
|
$435,000 | — | 31 Mar 2026 | |
| BlackRock, Inc. |
13F
|
Company |
0.25%
|
178,326
|
$420,849 | — | 31 Mar 2026 | |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC |
13F
|
Company |
0.24%
|
176,171
|
$415,764 | — | 31 Mar 2026 | |
| STATE STREET CORP |
13F
|
Company |
0.21%
|
151,728
|
$358,078 | — | 31 Mar 2026 | |
| MORGAN STANLEY |
13F
|
Company |
0.2%
|
144,584
|
$341,219 | — | 31 Mar 2026 | |
| Qube Research & Technologies Ltd |
13F
|
Company |
0.17%
|
120,388
|
$284,116 | — | 31 Mar 2026 | |
| DIMENSIONAL FUND ADVISORS LP |
13F
|
Company |
0.17%
|
119,756
|
$281,763 | — | 31 Mar 2026 | |
| CATALYST FINANCIAL PARTNERS LLC |
13F
|
Company |
0.12%
|
89,699
|
$211,690 | — | 31 Mar 2026 | |
| JANE STREET GROUP, LLC |
13F
|
Company |
0.12%
|
89,661
|
$211,599 | — | 31 Mar 2026 | |
| PFG Investments, LLC |
13F
|
Company |
0.11%
|
80,850
|
$190,806 | — | 31 Mar 2026 | |
| NORTHERN TRUST CORP |
13F
|
Company |
0.1%
|
75,212
|
$177,500 | — | 31 Mar 2026 | |
| Point72 Asset Management, L.P. |
13F
|
Company |
0.09%
|
67,375
|
$159,005 | — | 31 Mar 2026 | |
| Prospera Financial Services Inc |
13F
|
Company |
0.07%
|
50,000
|
$118,000 | — | 31 Mar 2026 | |
| Catalyst Funds Management Pty Ltd |
13F
|
Company |
0.06%
|
45,600
|
$107,616 | — | 31 Mar 2026 | |
| Verdad Advisers, LP |
13F
|
Company |
0.05%
|
37,278
|
$87,976 | — | 31 Mar 2026 | |
| UBS Group AG |
13F
|
Company |
0.05%
|
37,146
|
$87,665 | — | 31 Mar 2026 | |
| Rangeley Capital, LLC |
13F
|
Company |
0.05%
|
35,000
|
$82,600 | — | 31 Mar 2026 | |
| BARCLAYS PLC |
13F
|
Company |
0.04%
|
30,679
|
$72,402 | — | 31 Mar 2026 | |
| Intrepid Financial Planning Group LLC |
13F
|
Company |
0.04%
|
30,150
|
$71,154 | — | 31 Mar 2026 | |
| OMERS ADMINISTRATION Corp |
13F
|
Company |
0.04%
|
28,600
|
$67,496 | — | 31 Mar 2026 | |
| AXQ CAPITAL, LP |
13F
|
Company |
0.04%
|
28,487
|
$67,229 | — | 31 Mar 2026 | |
| Independent Advisor Alliance |
13F
|
Company |
0.03%
|
19,000
|
$44,840 | — | 31 Mar 2026 | |
| PINNACLE ASSOCIATES LTD |
13F
|
Company |
0.02%
|
18,020
|
$42,527 | — | 31 Mar 2026 | |
| Pinnacle Wealth Management Advisory Group, LLC |
13F
|
Company |
0.02%
|
18,020
|
$42,527 | — | 31 Mar 2026 | |
| AMERICAN CENTURY COMPANIES INC |
13F
|
Company |
0.02%
|
17,929
|
$42,312 | — | 31 Mar 2026 | |
| SIMPLEX TRADING, LLC |
13F
|
Company |
0.02%
|
17,414
|
$41,097 | — | 31 Mar 2026 |
Recent Insider Transactions by Companies or Individuals for Acumen Pharmaceuticals, Inc.
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Value $ | * Price $ | Shares | Shares Owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Ra Capital Management, L.P. | ABOS | Common Stock | Award | 46.5% | 6,060,606 | 19,103,785 | 16 Mar 2026 | See footnotes | ||
| Derek M. Meisner | ABOS | Common Stock | Sale | -1.19% | $6,813 | $3.26 | -2,090 | 173,999 | 06 Mar 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Options Exercise | 1.2% | 2,090 | 176,089 | 06 Mar 2026 | Direct | ||
| Derek M. Meisner | ABOS | Employee Stock Option (right to buy) | Options Exercise | -2.86% | -2,090 | 71,048 | 06 Mar 2026 | Direct | ||
| Derek M. Meisner | ABOS | Common Stock | Sale | -5.13% | $28,311 | $3.01 | -9,406 | 173,999 | 27 Feb 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Options Exercise | 5.41% | 9,406 | 183,405 | 27 Feb 2026 | Direct | ||
| Derek M. Meisner | ABOS | Employee Stock Option (right to buy) | Options Exercise | -11.4% | -9,406 | 73,138 | 27 Feb 2026 | Direct | ||
| Derek M. Meisner | ABOS | Common Stock | Sale | -1.51% | $8,017 | $3.00 | -2,671 | 173,999 | 28 Jan 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Options Exercise | 1.54% | 2,671 | 176,670 | 28 Jan 2026 | Direct | ||
| Derek M. Meisner | ABOS | Employee Stock Option (right to buy) | Options Exercise | -3.13% | -2,671 | 82,544 | 28 Jan 2026 | Direct | ||
| Derek M. Meisner | ABOS | Common Stock | Sale | -7.98% | $45,263 | $3.00 | -15,085 | 173,999 | 26 Jan 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Options Exercise | 8.67% | 15,085 | 189,084 | 26 Jan 2026 | Direct | ||
| Derek M. Meisner | ABOS | Employee Stock Option (right to buy) | Options Exercise | -15% | -15,085 | 85,215 | 26 Jan 2026 | Direct | ||
| Derek M. Meisner | ABOS | Common Stock | Sale | -3.14% | $10,718 | $1.90 | -5,633 | 173,999 | 23 Jan 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Sale | -0.58% | $1,939 | $1.84 | -1,054 | 179,632 | 22 Jan 2026 | Direct |
| Eric Siemers | ABOS | Common Stock | Sale | -0.35% | $1,629 | $1.82 | -895 | 255,371 | 22 Jan 2026 | Direct |
| Matt Zuga | ABOS | Common Stock | Sale | -0.55% | $3,138 | $1.86 | -1,687 | 304,924 | 22 Jan 2026 | Direct |
| Daniel Joseph OConnell | ABOS | Common Stock | Sale | -0.3% | $5,066 | $1.88 | -2,689 | 881,275 | 22 Jan 2026 | Direct |
| Russell Barton | ABOS | Common Stock | Sale | -0.22% | $850 | $1.84 | -462 | 205,092 | 22 Jan 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Sale | -1.23% | $4,063 | $1.81 | -2,247 | 180,686 | 21 Jan 2026 | Direct |
| Eric Siemers | ABOS | Common Stock | Sale | -0.9% | $4,204 | $1.80 | -2,331 | 256,266 | 21 Jan 2026 | Direct |
| Matt Zuga | ABOS | Common Stock | Sale | -0.8% | $4,469 | $1.81 | -2,473 | 306,611 | 21 Jan 2026 | Direct |
| Daniel Joseph OConnell | ABOS | Common Stock | Sale | -1.05% | $16,927 | $1.81 | -9,346 | 883,964 | 21 Jan 2026 | Direct |
| Russell Barton | ABOS | Common Stock | Sale | -1.11% | $4,181 | $1.81 | -2,315 | 205,554 | 21 Jan 2026 | Direct |
| Daniel Joseph OConnell | ABOS | Common Stock | Award | 50.5% | 299,800 | 893,310 | 20 Jan 2026 | Direct | ||
| Daniel Joseph OConnell | ABOS | Employee Stock Option (right to buy) | Award | 450,000 | 450,000 | 20 Jan 2026 | Direct | |||
| Matt Zuga | ABOS | Common Stock | Award | 47.2% | 99,133 | 309,084 | 16 Jan 2026 | Direct | ||
| Matt Zuga | ABOS | Employee Stock Option (right to buy) | Award | 148,700 | 148,700 | 16 Jan 2026 | Direct | |||
| Derek M. Meisner | ABOS | Common Stock | Award | 118.3% | 99,133 | 182,933 | 16 Jan 2026 | Direct | ||
| Derek M. Meisner | ABOS | Employee Stock Option (right to buy) | Award | 148,700 | 148,700 | 16 Jan 2026 | Direct | |||
| Eric Siemers | ABOS | Common Stock | Award | 62.2% | 99,133 | 258,597 | 16 Jan 2026 | Direct | ||
| Eric Siemers | ABOS | Employee Stock Option (right to buy) | Award | 148,700 | 148,700 | 16 Jan 2026 | Direct | |||
| Russell Barton | ABOS | Common Stock | Award | 68.6% | 84,600 | 207,869 | 16 Jan 2026 | Direct | ||
| Russell Barton | ABOS | Employee Stock Option (right to buy) | Award | 126,900 | 126,900 | 16 Jan 2026 | Direct | |||
| Amy Schacterle | ABOS | Common Stock | Award | 1098.3% | 84,600 | 92,303 | 16 Jan 2026 | Direct | ||
| Amy Schacterle | ABOS | Employee Stock Option (right to buy) | Award | 126,900 | 126,900 | 16 Jan 2026 | Direct | |||
| James J. Doherty | ABOS | Common Stock | Award | 308.8% | 166,867 | 220,900 | 16 Jan 2026 | Direct | ||
| James J. Doherty | ABOS | Employee Stock Option (right to buy) | Award | 250,300 | 250,300 | 16 Jan 2026 | Direct | |||
| Derek M. Meisner | ABOS | Common Stock | Sale | -9.26% | $14,658 | $1.71 | -8,548 | 83,800 | 12 Jan 2026 | Direct |
| Daniel Joseph OConnell | ABOS | Common Stock | Sale | -0.9% | $9,307 | $1.73 | -5,388 | 593,510 | 12 Jan 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Sale | -5.33% | $9,169 | $1.76 | -5,200 | 92,348 | 09 Jan 2026 | Direct |
| Daniel Joseph OConnell | ABOS | Common Stock | Sale | -2.12% | $22,832 | $1.76 | -12,941 | 598,898 | 09 Jan 2026 | Direct |
| Matt Zuga | ABOS | Common Stock | Sale | -3.18% | $12,513 | $1.82 | -6,888 | 209,951 | 08 Jan 2026 | Direct |
| Russell Barton | ABOS | Common Stock | Sale | -2.78% | $6,562 | $1.86 | -3,530 | 123,269 | 08 Jan 2026 | Direct |
| Derek M. Meisner | ABOS | Common Stock | Sale | -27.4% | $67,246 | $1.82 | -36,911 | 97,548 | 08 Jan 2026 | Direct |
| Daniel Joseph OConnell | ABOS | Common Stock | Sale | -1.31% | $14,815 | $1.82 | -8,143 | 611,839 | 08 Jan 2026 | Direct |
| James J. Doherty | ABOS | Common Stock | Sale | -10.7% | $11,769 | $1.82 | -6,467 | 54,033 | 08 Jan 2026 | Direct |
| James J. Doherty | ABOS | Common Stock | Sale | -2.73% | $3,379 | $1.99 | -1,700 | 60,500 | 07 Jan 2026 | Direct |
| Amy Schacterle | ABOS | Common Stock | Sale | -12.5% | $2,176 | $1.98 | -1,097 | 7,703 | 07 Jan 2026 | Direct |
| Matt Zuga | ABOS | Common Stock | Sale | -2.61% | $11,566 | $1.99 | -5,805 | 216,839 | 07 Jan 2026 | Direct |
* An asterisk sign (*) next to the price indicates that the price is likely invalid.