Rock Springs Capital Management LP / ALNY
Rock Springs Capital Management LP’s Alnylam Pharmaceuticals Inc Position
Does Rock Springs Capital Management LP own Alnylam Pharmaceuticals Inc (ALNY)? Yes — 74.0K shares worth $24M (+1.44% of its 13F portfolio) as of Q1 2026, up from 71.3K shares the prior filed quarter.
Position Value
$24M
Q1 2026
Shares
74.0K
% of Portfolio
+1.44%
Quarters Held
30
currently held
Position History ALNY
Reported value by quarter
| Quarter | Shares | Value | % of Portfolio |
|---|---|---|---|
| Q1 2026 | 74.0K | $24M | +1.44% |
| Q4 2025 | 71.3K | $28M | +1.45% |
| Q3 2025 | 74.3K | $34M | +1.98% |
| Q2 2025 | 100.0K | $33M | +2.03% |
| Q1 2025 | 143.3K | $39M | +2.21% |
| Q4 2024 | 256.2K | $60M | +2.30% |
| Q3 2024 | 250.0K | $69M | +2.24% |
| Q2 2024 | 250.0K | $61M | +1.83% |
| Q1 2024 | 244.0K | $36M | +0.93% |
| Q4 2023 | 235.0K | $45M | +1.11% |
| Q3 2023 | 279.5K | $49M | +1.33% |
| Q2 2023 | 345.0K | $66M | +1.56% |
| Q1 2023 | 345.0K | $69M | +1.65% |
| Q4 2022 | 332.5K | $79M | +1.90% |
| Q3 2022 | 332.5K | $67M | +1.72% |
| Q2 2022 | 332.5K | $48M | +1.41% |
| Q1 2022 | 332.5K | $54M | +1.37% |
| Q4 2021 | 332.5K | $56M | +1.30% |
| Q3 2021 | 311.0K | $59M | +1.23% |
| Q2 2021 | 300.0K | $51M | +1.01% |
| Q1 2021 | 300.0K | $42M | +0.92% |
| Q4 2020 | 335.0K | $44M | +0.92% |
| Q3 2020 | 339.8K | $49M | +1.26% |
| Q2 2020 | 345.0K | $51M | +1.40% |
| Q1 2020 | 381.5K | $42M | +1.72% |
| Q4 2019 | 364.0K | $42M | +1.32% |
| Q3 2019 | 330.5K | $27M | +1.06% |
| Q2 2019 | 327.7K | $24M | +0.86% |
| Q1 2019 | 233.5K | $22M | +0.84% |
| Q4 2018 | 194.0K | $14M | +0.67% |
Common-stock position only; options are excluded. Quarters where the fund filed no 13F or reported no position are absent. See Rock Springs Capital Management LP’s full portfolio or all institutional holders of ALNY.