13F reference period
Q3 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 Q3 2026
Institutions Reporting
42
Shares (Excl. Options)
12.46M
Full value: 12,457,867 · shares · 30 Sep 2026Price
$2.22
The headline uses the Q3 2026 reference period after its reporting deadline. Available reports may still be incomplete or amended.
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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 Sep 2026
- Q3 2026
- Total 13F shares
- 12,457,867
- Total 13F value
- $27,656,921
- Portfolio coverage rank
- 0%
- Share change
- +366,680
- Value change
- +$746,033
- Number of holders
- 42
- Shares outstanding
- 72,227,200
- SEC-reported price per share
- $2.02
- Insider filing price
- $2.02
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
Filing notes and source
Key facts
- ABOS - Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share is tracked under CUSIP 00509G209.
- 42 institutions reported positions in Q3 2026.
- 4 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 96 to 42 between Q2 2026 and Q3 2026.
- SEC-reported value moved from to
$127.78M
Full value: $127,776,787 · USD · 30 Jun 2026.$27.66M
Full value: $27,656,921 · USD · 30 Sep 2026
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 42 institutions filings for Q3 2026.
Security key
00509G209
13F reference period
Q3 2026
13F holders
42
13D/G owners
4
CIK / CUSIP context first
Open Q3 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 Sep 2026,
42
institutional investors reported holding
shares of
Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share (ABOS).
This represents
17%
of the company’s total
outstanding shares.
12.46M
Full value: 12,457,867 · shares · 30 Sep 202672.23M
Full value: 72,227,200 · shares · Stored outstanding share count13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
17%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| Sands Capital Alternatives, LLC | 5.2% | 3,720,105 | 0% | 1.2% | $8,258,633 |
| VANGUARD CAPITAL MANAGEMENT LLC | 2.5% | 1,816,442 | +8.6% | 0% | $4,032,501 |
| Knollwood Investment Advisory, LLC | 2.3% | 1,628,510 | 0% | 0.31% | $3,615,292 |
| GEODE CAPITAL MANAGEMENT, LLC | 1.6% | 1,154,919 | +1.1% | 0% | $2,564,361 |
| Hudson Bay Capital Management LP | 1.4% | 1,025,000 | +7.3% | 0.01% | $2,275,500 |
| STATE STREET CORP | 1.2% | 837,120 | +39% | 0% | $1,858,406 |
| RENAISSANCE TECHNOLOGIES LLC | 0.85% | 614,654 | -8.9% | 0% | $1,364,532 |
| DIMENSIONAL FUND ADVISORS LP | 0.45% | 323,999 | +11% | 0% | $719,403 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 0.45% | 323,420 | +0.82% | 0% | $717,992 |
| VANGUARD FIDUCIARY TRUST CO | 0.4% | 291,201 | -0.01% | 0% | $646,466 |
| PFG Investments, LLC | 0.15% | 107,151 | +14% | 0.01% | $237,875 |
| CATALYST FINANCIAL PARTNERS LLC | 0.14% | 99,699 | +11% | 0.02% | $221,332 |
| MORGAN STANLEY | 0.12% | 89,226 | -35% | 0% | $198,081 |
| Empowered Funds, LLC | 0.12% | 86,389 | 0% | $191,784 | |
| DEUTSCHE BANK AG\ | 0.06% | 40,169 | -13% | 0% | $89,175 |
| AMERICAN CENTURY COMPANIES INC | 0.05% | 38,824 | +61% | 0% | $86,189 |
| Intrepid Financial Planning Group LLC | 0.04% | 30,150 | 0% | 0.02% | $66,933 |
| Invesco Ltd. | 0.03% | 24,282 | -1.2% | 0% | $53,906 |
| Spark Investment Management LLC | 0.03% | 21,700 | +48% | 0.08% | $48,174 |
| Police & Firemen's Retirement System of New Jersey | 0.03% | 19,393 | 0% | 0% | $43,052 |
| STIFEL FINANCIAL CORP | 0.03% | 19,275 | +49% | 0% | $42,791 |
| Independent Advisor Alliance | 0.03% | 19,000 | 0% | 0% | $42,180 |
| Pinnacle Wealth Management Advisory Group, LLC | 0.02% | 18,021 | +0.01% | 0% | $40,007 |
| PINNACLE ASSOCIATES LTD | 0.02% | 18,021 | +0.01% | 0% | $40,007 |
| Factor Wealth Management LTD | 0.02% | 16,500 | 0% | 0.01% | $36,630 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
21
Headline period
Q3 2026
Rows shown
1-21 of 21
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q3 | 12,457,867 | $27,656,921 | +$746,033 | $2.22 | 42 |
| 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 |