Alnylam Pharmaceuticals
ALNY
851 hedge funds and large institutions have $52.7B invested in Alnylam Pharmaceuticals in 2025 Q4 according to their latest regulatory filings, with 171 funds opening new positions, 290 increasing their positions, 291 reducing their positions, and 118 closing their positions.
54% more call options, than puts
Call options by funds: $760M | Put options by funds: $494M
45% more first-time investments, than exits
New positions opened: 171 | Existing positions closed: 118
3% more funds holding
Funds holding: 823 → 851 (+28)
1.22% more ownership
Funds ownership: 99.09% → 100.31% (+1.2%)
0% less repeat investments, than reductions
Existing positions increased: 290 | Existing positions reduced: 291
11% less capital invested
Capital invested by funds: $59.2B → $52.7B (-$6.53B)
69% less funds holding in top 10
Funds holding in top 10: 13 → 4 (-9)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Invesco
Atlanta,
Georgia
|
+$1.62B |
| 2 |
BlackRock
New York
|
+$220M |
| 3 |
UBS Group
Zurich,
Switzerland
|
+$149M |
| 4 |
D.E. Shaw & Co
New York
|
+$108M |
| 5 |
Morgan Stanley
New York
|
+$108M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
RP
Regeneron Pharmaceuticals
Tarrytown,
New York
|
-$635M |
| 2 |
Fidelity Investments
Boston,
Massachusetts
|
-$383M |
| 3 |
Bank of America
Charlotte,
North Carolina
|
-$360M |
| 4 |
Jane Street
New York
|
-$287M |
| 5 |
Macquarie Group
Sydney, NSW 2000,
Australia
|
-$276M |
ALNY Hedge Fund Activity: Q4 2025 in Review
851 of the 8,266 institutional investors tracked by Wall St. Rank reported a position in Alnylam Pharmaceuticals (ALNY) for Q4 2025, worth a combined $52.7B — down 11% from $59.2B a quarter earlier.
Buyers outnumbered sellers: 171 funds opened new ALNY positions and 118 closed out — a net gain of 53 holders — while 290 added to existing stakes and 291 trimmed.
The largest buyer was Invesco, adding an estimated $1.62B. The largest seller was Regeneron Pharmaceuticals, exiting entirely with an estimated $635M sold.
- 851 institutional investors held Alnylam Pharmaceuticals (ALNY) as of Q4 2025, up from 823 in Q3 2025.
- Funds reported $52.7B of Alnylam Pharmaceuticals stock for Q4 2025, down 11% quarter-over-quarter.
- 171 funds opened new Alnylam Pharmaceuticals positions in Q4 2025 and 118 closed out, a net change of +53 holders.
- The largest Alnylam Pharmaceuticals buyer in Q4 2025 was Invesco, an estimated $1.62B added.
- The largest Alnylam Pharmaceuticals seller in Q4 2025 was Regeneron Pharmaceuticals, an estimated $635M sold.
Based on aggregated 13F filings for Q4 2025.