Latest Period
Q2 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 Q2 2026
Institutions Reporting
96
Shares (Excl. Options)
47,856,762
Price
$2.67
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- Security type / class
- Equity / Common Stock, $0.0001 par value per share
- Symbol
- ABOS on Nasdaq
- All holders as of 30 Jun 2026
- Q2 2026
- Total 13F shares
- 47,856,762
- Total 13F value
- $127,776,787
- Portfolio coverage rank
- 0%
- Share change
- +1,845,677
- Value change
- +$5,415,646
- Number of holders
- 96
- Shares outstanding
- 72,227,200
- SEC-reported price per share
- $2.17
- Insider filing price
- $2.17
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.
- 96 institutions reported positions in Q2 2026.
- 4 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 84 to 96 between Q1 2026 and Q2 2026.
- SEC-reported value moved from $108,541,469 to $127,776,787.
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 96 institutions filings for Q2 2026.
Security key
00509G209
Latest holder period
Q2 2026
13F holders
96
13D/G owners
4
CIK / CUSIP context first
Open Q2 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 30 Jun 2026, 96 institutional investors reported holding 47,856,762 shares of Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share (ABOS). This represents 66% 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
64%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 29% | 20,992,669 | 0% | 0.49% | $56,050,426 |
| Sands Capital Alternatives, LLC | 5.2% | 3,720,105 | 0% | 1.6% | $9,932,680 |
| BlackRock, Inc. | 3.4% | 2,490,115 | +1296% | 0% | $6,648,607 |
| Alyeska Investment Group, L.P. | 3.4% | 2,454,754 | 0% | 0.02% | $6,554,193 |
| FRANKLIN RESOURCES INC | 3.2% | 2,305,096 | 0% | 0% | $6,154,606 |
| ADAR1 Capital Management, LLC | 2.9% | 2,111,334 | -2.1% | 0.27% | $5,637,262 |
| VANGUARD CAPITAL MANAGEMENT LLC | 2.3% | 1,672,072 | +11% | 0% | $4,464,432 |
| Knollwood Investment Advisory, LLC | 2.3% | 1,628,510 | 0% | 0.39% | $4,348,122 |
| GEODE CAPITAL MANAGEMENT, LLC | 1.6% | 1,141,858 | +174% | 0% | $3,049,286 |
| Ikarian Capital, LLC | 1.5% | 1,053,797 | 0% | 0.46% | $2,813,638 |
| Hudson Bay Capital Management LP | 1.3% | 955,000 | -1.4% | 0.01% | $2,549,850 |
| Pathstone Holdings, LLC | 1.2% | 859,110 | 0% | 0.01% | $2,293,824 |
| RENAISSANCE TECHNOLOGIES LLC | 0.93% | 675,025 | +42% | 0% | $1,802,317 |
| TWO SIGMA INVESTMENTS, LP | 0.86% | 622,882 | +17% | 0% | $1,663,095 |
| STATE STREET CORP | 0.83% | 600,528 | +296% | 0% | $1,603,410 |
| NORTHERN TRUST CORP | 0.5% | 360,744 | +380% | 0% | $963,187 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 0.44% | 320,795 | 0% | $856,523 | |
| DIMENSIONAL FUND ADVISORS LP | 0.4% | 291,559 | +143% | 0% | $778,969 |
| VANGUARD FIDUCIARY TRUST CO | 0.4% | 291,240 | +46% | 0% | $777,611 |
| BANK OF AMERICA CORP /DE/ | 0.38% | 274,781 | -14% | 0% | $733,665 |
| BOOTHBAY FUND MANAGEMENT, LLC | 0.38% | 273,012 | 0% | 0.01% | $728,942 |
| ACADIAN ASSET MANAGEMENT LLC | 0.37% | 270,338 | +45% | 0% | $718,000 |
| NOMURA HOLDINGS INC | 0.26% | 189,712 | 0% | $506,531 | |
| GOLDMAN SACHS GROUP INC | 0.25% | 183,927 | -11% | 0% | $491,085 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 0.24% | 176,171 | 0% | 0.01% | $470,377 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
20
Latest
Q2 2026
Rows shown
1-20 of 20
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q2 | 47,856,762 | $127,776,787 | +$5,415,646 | $2.67 | 96 |
| 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 |