Acumen Pharmaceuticals
ABOS
84 hedge funds and large institutions have $109M invested in Acumen Pharmaceuticals in 2026 Q1 according to their latest regulatory filings, with 21 funds opening new positions, 31 increasing their positions, 12 reducing their positions, and 7 closing their positions.
200% more first-time investments, than exits
New positions opened: 21 | Existing positions closed: 7
158% more repeat investments, than reductions
Existing positions increased: 31 | Existing positions reduced: 12
44% more capital invested
Capital invested by funds: $75.2M → $109M (+$33.3M)
18% more funds holding
Funds holding: 71 → 84 (+13)
4.83% more ownership
Funds ownership: 58.87% → 63.7% (+4.8%)
31% less call options, than puts
Call options by funds: $246K | Put options by funds: $355K
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
RCM
RA Capital Management
Boston,
Massachusetts
|
+$15.5M |
| 2 |
Alyeska Investment Group
Chicago,
Illinois
|
+$3.86M |
| 3 |
ACM
ADAR1 Capital Management
Austin,
Texas
|
+$3.23M |
| 4 |
IC
Ikarian Capital
Dallas,
Texas
|
+$2.04M |
| 5 |
Two Sigma Investments
New York
|
+$989K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
-$2.22M |
| 2 |
Citadel Advisors
Miami,
Florida
|
-$881K |
| 3 |
LCM
Laurion Capital Management
New York
|
-$871K |
| 4 |
Jane Street
New York
|
-$134K |
| 5 |
XT
XTX Topco
George Town,
Cayman Islands
|
-$105K |
ABOS Hedge Fund Activity: Q1 2026 in Review
84 of the 8,127 institutional investors tracked by Wall St. Rank reported a position in Acumen Pharmaceuticals (ABOS) for Q1 2026, worth a combined $109M — up 44% from $75.2M a quarter earlier.
Buyers outnumbered sellers: 21 funds opened new ABOS positions and 7 closed out — a net gain of 14 holders — while 31 added to existing stakes and 12 trimmed.
The largest buyer was RA Capital Management, adding an estimated $15.5M. The largest seller was Fidelity Investments, cutting an estimated $2.22M.
- 84 institutional investors held Acumen Pharmaceuticals (ABOS) as of Q1 2026, up from 71 in Q4 2025.
- Funds reported $109M of Acumen Pharmaceuticals stock for Q1 2026, up 44% quarter-over-quarter.
- 21 funds opened new Acumen Pharmaceuticals positions in Q1 2026 and 7 closed out, a net change of +14 holders.
- The largest Acumen Pharmaceuticals buyer in Q1 2026 was RA Capital Management, an estimated $15.5M added.
- The largest Acumen Pharmaceuticals seller in Q1 2026 was Fidelity Investments, an estimated $2.22M sold.
Based on aggregated 13F filings for Q1 2026.