Latest Period
Q1 2026
Security Snapshot
Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share (ABOS) Institutional Ownership
CUSIP: 00509G209
13F Institutional Holders and Ownership History from Q3 2021 to Q1 2026
Institutions Reporting
84
Shares (Excl. Options)
46,001,051
Price
$2.36
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- Security type / class
- Equity / Common Stock, $0.0001 par value per share
- Symbol
- ABOS on Nasdaq
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 46,001,051
- Total 13F value
- $108,541,469
- Portfolio coverage rank
- 0%
- Share change
- +10,282,919
- Value change
- +$24,478,369
- Number of holders
- 84
- Shares outstanding
- 72,227,200
- SEC-reported price per share
- $2.56
- Insider filing price
- $2.56
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
3 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- ABOS - Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share is tracked under CUSIP 00509G209.
- 84 institutions reported positions in Q1 2026.
- 4 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 70 to 84 between Q4 2025 and Q1 2026.
- SEC-reported value moved from $75,239,476 to $108,541,469.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 84 institutions filings for Q1 2026.
Security key
00509G209
Latest holder period
Q1 2026
13F holders
84
13D/G owners
4
CIK / CUSIP context first
Open Q1 2026 holders
ABOS full holder history
Acumen Pharmaceuticals, Inc. SEC filings
Acumen Pharmaceuticals, Inc. company facts
Acumen Pharmaceuticals, Inc. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 00509G209:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
4
Security
ABOS
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 30% | +19% | $55,075,356 | +$15,883,432 | 21,101,669 | +41% | RA Capital Management, L.P. | 13 Mar 2026 |
| MURRAY JAMES B JR | 5% | $9,425,650 | 3,611,360 | James B. Murray Jr. | 04 Apr 2025 | |||
| Sands Capital Alternatives, LLC | 5.6% | $3,861,295 | 3,417,075 | Sands Capital Alternatives, LLC | 30 Jun 2025 | |||
| FRANKLIN RESOURCES INC | 3.8% | $3,941,714 | 2,305,096 | Franklin Resources, Inc. | 30 Sep 2025 |
As of 31 Mar 2026, 84 institutional investors reported holding 46,001,051 shares of Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share (ABOS). This represents 64% of the company’s total 72,227,200 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
61%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 29% | 20,992,669 | +41% | 0.52% | $49,542,699 |
| Sands Capital Alternatives, LLC | 5.2% | 3,720,105 | +8.9% | 2.1% | $8,779,448 |
| Alyeska Investment Group, L.P. | 3.4% | 2,454,754 | +161% | 0.02% | $5,776,765 |
| FRANKLIN RESOURCES INC | 3.2% | 2,305,096 | 0% | 0% | $5,440,027 |
| ADAR1 Capital Management, LLC | 3% | 2,156,334 | +142% | 0.31% | $5,088,948 |
| Knollwood Investment Advisory, LLC | 2.3% | 1,628,510 | 0% | 0.39% | $3,843,284 |
| VANGUARD CAPITAL MANAGEMENT LLC | 2.1% | 1,506,277 | 0% | 0% | $3,554,814 |
| FMR LLC | 1.6% | 1,157,346 | -43% | 0% | $2,731,337 |
| Ikarian Capital, LLC | 1.5% | 1,053,797 | +314% | 0.36% | $2,486,960 |
| Hudson Bay Capital Management LP | 1.3% | 968,940 | +34% | 0.01% | $2,286,698 |
| Pathstone Holdings, LLC | 1.2% | 859,110 | 0% | 0.01% | $2,027,500 |
| SG Americas Securities, LLC | 1% | 719,257 | +79% | 0% | $1,697,000 |
| MILLENNIUM MANAGEMENT LLC | 0.91% | 659,675 | +13% | 0% | $1,556,833 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | 0.83% | 601,476 | +61% | 0% | $1,419,483 |
| TWO SIGMA INVESTMENTS, LP | 0.73% | 530,812 | +271% | 0% | $1,252,716 |
| Laurion Capital Management LP | 0.73% | 525,444 | -39% | 0.12% | $1,240,048 |
| RENAISSANCE TECHNOLOGIES LLC | 0.66% | 473,946 | +12% | 0% | $1,118,513 |
| GEODE CAPITAL MANAGEMENT, LLC | 0.58% | 416,238 | +1.5% | 0% | $982,755 |
| BANK OF AMERICA CORP /DE/ | 0.44% | 320,216 | +33% | 0% | $755,710 |
| BOOTHBAY FUND MANAGEMENT, LLC | 0.38% | 273,012 | +590% | 0.02% | $644,308 |
| GOLDMAN SACHS GROUP INC | 0.29% | 206,683 | +75% | 0% | $487,772 |
| VANGUARD FIDUCIARY TRUST CO | 0.28% | 199,226 | 0% | 0% | $470,173 |
| MARSHALL WACE, LLP | 0.27% | 192,889 | +823% | 0% | $455,218 |
| ACADIAN ASSET MANAGEMENT LLC | 0.26% | 185,850 | +22% | 0% | $435,000 |
| BlackRock, Inc. | 0.25% | 178,326 | +5.2% | 0% | $420,849 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
19
Latest
Q1 2026
Rows shown
1-19 of 19
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 46,001,051 | $108,541,469 | +$24,478,369 | $2.36 | 84 |
| 2025 Q4 | 35,659,733 | $75,239,476 | -$34,280 | $2.11 | 70 |
| 2025 Q3 | 35,732,361 | $61,097,340 | -$2,875,631 | $1.71 | 68 |
| 2025 Q2 | 37,585,884 | $43,599,129 | -$2,103,479 | $1.16 | 69 |
| 2025 Q1 | 39,403,584 | $43,344,870 | -$3,628,850 | $1.10 | 79 |
| 2024 Q4 | 42,499,401 | $73,099,738 | -$2,305,406 | $1.72 | 78 |
| 2024 Q3 | 43,605,225 | $107,681,203 | -$212,803 | $2.48 | 72 |
| 2024 Q2 | 43,581,156 | $105,487,337 | -$2,322,503 | $2.42 | 81 |
| 2024 Q1 | 43,364,829 | $175,565,762 | +$20,042,386 | $4.05 | 78 |
| 2023 Q4 | 38,441,008 | $147,599,716 | -$20,522,527 | $3.84 | 67 |
| 2023 Q3 | 43,186,479 | $179,213,677 | +$71,103,757 | $4.15 | 64 |
| 2023 Q2 | 26,328,948 | $126,640,120 | -$5,262,013 | $4.81 | 52 |
| 2023 Q1 | 27,781,261 | $112,787,020 | -$4,579,764 | $4.06 | 61 |
| 2022 Q4 | 28,727,743 | $155,145,749 | -$5,374,332 | $5.40 | 59 |
| 2022 Q3 | 27,496,751 | $275,793,298 | +$19,526,193 | $10.03 | 48 |
| 2022 Q2 | 25,628,401 | $120,458,000 | -$6,031,616 | $4.70 | 44 |
| 2022 Q1 | 27,062,428 | $105,815,702 | -$3,031,020 | $3.91 | 53 |
| 2021 Q4 | 25,569,796 | $172,840,000 | -$1,670,403 | $6.76 | 50 |
| 2021 Q3 | 24,050,108 | $357,352,000 | +$306,574,000 | $14.86 | 40 |