Alnylam Pharmaceuticals
ALNY
791 hedge funds and large institutions have $43.4B invested in Alnylam Pharmaceuticals in 2026 Q1 according to their latest regulatory filings, with 106 funds opening new positions, 321 increasing their positions, 258 reducing their positions, and 155 closing their positions.
120% more call options, than puts
Call options by funds: $450M | Put options by funds: $205M
24% more repeat investments, than reductions
Existing positions increased: 321 | Existing positions reduced: 258
1.4% less ownership
Funds ownership: 100.48% → 99.08% (-1.4%)
7% less funds holding
Funds holding: 851 → 791 (-60)
18% less capital invested
Capital invested by funds: $52.9B → $43.4B (-$9.52B)
25% less funds holding in top 10
Funds holding in top 10: 4 → 3 (-1)
32% less first-time investments, than exits
New positions opened: 106 | Existing positions closed: 155
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
+$1.17B |
| 2 |
Capital Research Global Investors
Los Angeles,
California
|
+$916M |
| 3 |
JP Morgan Chase
New York
|
+$546M |
| 4 |
Two Sigma Investments
New York
|
+$468M |
| 5 |
ClearBridge Investments
New York
|
+$258M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Capital World Investors
Los Angeles,
California
|
-$1.87B |
| 2 |
Fidelity Investments
Boston,
Massachusetts
|
-$450M |
| 3 |
Arrowstreet Capital
Boston,
Massachusetts
|
-$448M |
| 4 |
Invesco
Atlanta,
Georgia
|
-$360M |
| 5 |
1832 Asset Management
Toronto,
Ontario, Canada
|
-$175M |
ALNY Hedge Fund Activity: Q1 2026 in Review
791 institutional investors reported a position in Alnylam Pharmaceuticals (ALNY) for Q1 2026, worth a combined $43.4B — down 18% from $52.9B a quarter earlier.
Sellers outnumbered buyers: 155 funds closed out of ALNY and 106 opened new positions — a net loss of 49 holders — while 258 trimmed existing stakes and 321 added.
The largest buyer was T. Rowe Price Investment Management, adding an estimated $1.17B. The largest seller was Capital World Investors, cutting an estimated $1.87B.
- 791 institutional investors held Alnylam Pharmaceuticals (ALNY) as of Q1 2026, down from 851 in Q4 2025.
- Funds reported $43.4B of Alnylam Pharmaceuticals stock for Q1 2026, down 18% quarter-over-quarter.
- 106 funds opened new Alnylam Pharmaceuticals positions in Q1 2026 and 155 closed out, a net change of -49 holders.
- The largest Alnylam Pharmaceuticals buyer in Q1 2026 was T. Rowe Price Investment Management, an estimated $1.17B added.
- The largest Alnylam Pharmaceuticals seller in Q1 2026 was Capital World Investors, an estimated $1.87B sold.
Based on aggregated 13F filings for Q1 2026.