Rock Springs Capital Management’s Alnylam Pharmaceuticals ALNY Stock Holding History
Bought
Maintained
Sold
| Quarter | Market Value | Status | Shares |
Change in Stake | Trade Value | Portfolio Weight | Portfolio Position | |
|---|---|---|---|---|---|---|---|---|
|
2026
Q2 | $20.1M | Sell |
66,750
-7,250
| -10% | -$2.19M | 0.98% | 33 |
|
|
2026
Q1 | $24.5M | Buy |
74,000
+2,750
| +4% | +$936K | 1.44% | 21 |
|
|
2025
Q4 | $28.3M | Sell |
71,250
-3,000
| -4% | -$1.33M | 1.45% | 23 |
|
|
2025
Q3 | $33.9M | Sell |
74,250
-25,750
| -26% | -$10.5M | 1.98% | 17 |
|
|
2025
Q2 | $32.6M | Sell |
100,000
-43,250
| -30% | -$12M | 2.03% | 17 |
|
|
2025
Q1 | $38.7M | Sell |
143,250
-112,950
| -44% | -$29M | 2.21% | 15 |
|
|
2024
Q4 | $60.3M | Buy |
256,200
+6,200
| +2% | +$1.63M | 2.3% | 12 |
|
|
2024
Q3 | $68.8M | Hold |
250,000
| – | – | 2.24% | 9 |
|
|
2024
Q2 | $60.8M | Buy |
250,000
+6,000
| +2% | +$947K | 1.83% | 13 |
|
|
2024
Q1 | $36.5M | Buy |
244,000
+9,000
| +4% | +$1.5M | 0.93% | 40 |
|
|
2023
Q4 | $45M | Sell |
235,000
-44,500
| -16% | -$7.58M | 1.11% | 31 |
|
|
2023
Q3 | $49.5M | Sell |
279,500
-65,500
| -19% | -$12.5M | 1.33% | 26 |
|
|
2023
Q2 | $65.5M | Hold |
345,000
| – | – | 1.56% | 22 |
|
|
2023
Q1 | $69.1M | Buy |
345,000
+12,500
| +4% | +$2.63M | 1.65% | 20 |
|
|
2022
Q4 | $79M | Hold |
332,500
| – | – | 1.9% | 19 |
|
|
2022
Q3 | $66.6M | Hold |
332,500
| – | – | 1.72% | 16 |
|
|
2022
Q2 | $48.5M | Hold |
332,500
| – | – | 1.41% | 24 |
|
|
2022
Q1 | $54.3M | Hold |
332,500
| – | – | 1.37% | 26 |
|
|
2021
Q4 | $56.4M | Buy |
332,500
+21,500
| +7% | +$4M | 1.3% | 24 |
|
|
2021
Q3 | $58.7M | Buy |
311,000
+11,000
| +4% | +$2.06M | 1.23% | 26 |
|
|
2021
Q2 | $50.9M | Hold |
300,000
| – | – | 1.01% | 31 |
|
|
2021
Q1 | $42.4M | Sell |
300,000
-35,000
| -10% | -$5.27M | 0.92% | 36 |
|
|
2020
Q4 | $43.5M | Sell |
335,000
-4,814
| -1% | -$643K | 0.92% | 37 |
|
|
2020
Q3 | $49.5M | Sell |
339,814
-5,186
| -2% | -$737K | 1.26% | 24 |
|
|
2020
Q2 | $51.1M | Sell |
345,000
-36,500
| -10% | -$4.92M | 1.4% | 18 |
|
|
2020
Q1 | $41.5M | Buy |
381,500
+17,500
| +5% | +$2.02M | 1.72% | 15 |
|
|
2019
Q4 | $41.9M | Buy |
364,000
+33,500
| +10% | +$3.34M | 1.32% | 20 |
|
|
2019
Q3 | $26.6M | Buy |
330,500
+2,800
| +0.9% | +$222K | 1.06% | 29 |
|
|
2019
Q2 | $23.8M | Buy |
327,700
+94,200
| +40% | +$7.23M | 0.86% | 45 |
|
|
2019
Q1 | $21.8M | Buy |
233,500
+39,500
| +20% | +$3.3M | 0.84% | 42 |
|
|
2018
Q4 | $14.1M | Sell |
194,000
-2,500
| -1% | -$192K | 0.67% | 48 |
|
|
2018
Q3 | $17.2M | Buy |
196,500
+23,000
| +13% | +$2.31M | 0.62% | 57 |
|
|
2018
Q2 | $17.1M | Buy |
173,500
+30,500
| +21% | +$3.03M | 0.66% | 51 |
|
|
2018
Q1 | $17M | Buy |
143,000
+13,000
| +10% | +$1.68M | 0.73% | 49 |
|
|
2017
Q4 | $16.5M | Buy |
130,000
+25,000
| +24% | +$3.14M | 0.75% | 46 |
|
|
2017
Q3 | $12.3M | Hold |
105,000
| – | – | 0.57% | 57 |
|
|
2017
Q2 | $8.38M | Buy |
+105,000
| New | +$6.71M | 0.42% | 70 |
|
Other funds holding ALNY
Rock Springs Capital Management's ALNY Position: Q2 2026 in Review
Rock Springs Capital Management reduced its Alnylam Pharmaceuticals (ALNY) stake by 9.8% in Q2 2026, selling an estimated $2.19M and leaving 66,750 shares worth $20.1M. The position accounts for 0.98% of the portfolio, ranked #33.
Rock Springs Capital Management first reported a position in ALNY in Q2 2017 and has held it in 37 quarters since. The position peaked at $79M in Q4 2022. 785 funds tracked by Wall St. Rank hold ALNY as of Q2 2026.
- Rock Springs Capital Management held 66,750 shares of Alnylam Pharmaceuticals worth $20.1M as of Q2 2026.
- Rock Springs Capital Management sold 7,250 Alnylam Pharmaceuticals shares in Q2 2026, an estimated $2.19M.
- Alnylam Pharmaceuticals made up 0.98% of Rock Springs Capital Management's portfolio in Q2 2026, its #33 holding.
- Rock Springs Capital Management first reported a position in Alnylam Pharmaceuticals in Q2 2017 and has held it in 37 quarters since.
- Rock Springs Capital Management's Alnylam Pharmaceuticals position peaked at $79M in Q4 2022.
- 785 funds tracked by Wall St. Rank held Alnylam Pharmaceuticals as of Q2 2026.
Based on Rock Springs Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.