ABOS Institutional Ownership
Who owns Acumen Pharmaceuticals, Inc. and what the big funds did with it last quarter, from every SEC 13F filing. 96 funds reported holding ABOS at Jun 30, 2026, together owning 66.2% of the company.
- ▲51 buying vs 32 selling
- ▲Held by funds +2.6 pts
- ▲Funds holding +12
- ●Superinvestors: 2 added, 2 cut
- ●Put/call not meaningful
What the filings show, not a forecast. Positions can be up to 45 days old and leave out short sales.
Funds holding and ownership
8 quartersQuarter over quarter
all 13F filers| Q2 2026 | This quarter | Q1 2026 | Change |
|---|---|---|---|
| Funds holding | 96 | 84 | +14.3% |
| In funds' top 10 | 0 | 0 | – |
| 13F shares | 47.9M | 46M | +4.0% |
| Held by funds | 66.2% | 63.6% | +2.6 pts |
| New positions | 30 | 18 | +66.7% |
| Increased | 21 | 31 | −32.3% |
| Reduced | 15 | 12 | +25.0% |
| Sold out | 17 | 7 | +142.9% |
| Calls (shares) | 0 | 0 | – |
| Puts (shares) | 0 | 0 | – |
| Put/call ratio | – | – | – |
Buyers vs sellers
adding or new vs cutting or sold outSuperinvestors in ABOS
All superinvestors →
Who owns ABOS
share of fund held shares- Index and passive funds15.3%
- Active managers and hedge funds81.9%
- Banks and brokers2.7%
- Pensions, insurers and other0.1%
The top 10 holders own 82.7% of all ABOS shares that funds reported. Groups are our own grouping of filers by name.
Filed so far for Q3 2026
7 funds changed their position- Y-Intercept (Hong Kong) LtdSold out−30K sh
- GAMMA Investing LLCNew+877 sh
- SJS Investment Consulting Inc.New+183 sh
- Caitong International Asset Management Co., LtdTrimmed−37 sh
- Farther Finance Advisors, LLCAdded+25 sh
🔒 Free account: see all 7.
Top holders
Q2 2026| # | Fund | Of company | Shares | Value | Change |
|---|---|---|---|---|---|
| 1 | RA Capital Management, L.P. | 29.02% | 21M | $56.1M | 0 |
| 2 | Sands Capital Alternatives, LLC | 5.14% | 3.7M | $9.9M | 0 |
| 3 | BlackRock, Inc. | 3.44% | 2.5M | $6.6M | +2.3M |
| 4 | Alyeska Investment Group, L.P. | 3.39% | 2.5M | $6.6M | 0 |
| 5 | Franklin Resources Inc | 3.19% | 2.3M | $6.2M | 0 |
| 6 | ADAR1 Capital Management, LLC | 2.92% | 2.1M | $5.6M | −45K |
| 7 | Vanguard Capital Management LLC | 2.31% | 1.7M | $4.5M | +166K |
| 8 | Knollwood Investment Advisory, LLC | 2.25% | 1.6M | $4.3M | 0 |
| 9 | Geode Capital Management, LLC | 1.58% | 1.1M | $3M | +726K |
| 10 | Ikarian Capital, LLC | 1.46% | 1.1M | $2.8M | 0 |
- BlackRock, Inc.+2.3M sh+$6.2M
- Geode Capital Management, LLC+726K sh+$1.9M
- State Street Corp+449K sh+$1.2M
- Vanguard Portfolio Management LLC+321K sh+$857K
- Northern Trust Corp+286K sh+$762K
- Renaissance Technologies LLC+201K sh+$537K
- Nomura Holdings Inc+190K sh+$507K
- Dimensional Fund Advisors LP+172K sh+$459K
- Fmr LLC−1.1M sh−$3.1M
- SG Americas Securities, LLC−719K sh−$1.7M
- Millennium Management LLC−599K sh−$1.6M
- Susquehanna International Group, LLP−475K sh−$1.3M
- Laurion Capital Management LP−525K sh−$1.2M
- Marshall Wace, LLP−145K sh−$387K
- Qube Research & Technologies Ltd−82K sh−$218K
- Jane Street Group, LLC−90K sh−$212K
ABOS institutional ownership FAQ
Who owns the most ABOS stock?
In Q2 2026 13F filings the largest holder of ABOS was RA Capital Management, L.P., followed by Sands Capital Alternatives, LLC and BlackRock, Inc.. Index fund managers are usually the biggest holders of large companies.
What percentage of ABOS is owned by institutions?
Funds that file 13F reports held 66.2% of ABOS's shares at Jun 30, 2026, compared with 63.6% a quarter earlier. That counts every manager with more than $100 million in US stocks.
Are hedge funds buying ABOS?
In Q2 2026, 51 funds bought ABOS (30 of them new positions) and 32 sold (17 sold out completely). Among well known investors, 2 added and 2 cut. Our fund sentiment for ABOS is bullish.
What is ABOS's institutional put/call ratio?
Too few option positions were reported for a meaningful ratio.
How current is this ABOS ownership data?
13F filings show holdings at the end of each quarter and are due within 45 days, so positions can be up to six weeks old when they appear. We add each new filing within minutes, and the "filed so far" list shows funds that have already reported the next quarter.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Fund sentiment summarises what 13F filings show and is not a forecast. Holdings come from SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.