Alnylam Pharmaceuticals Inc
Ownership
Ownership Structure
Who owns Alnylam Pharmaceuticals Inc (ALNY)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 99.6% of the shares are freely tradable; institutional investors hold 102.1%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| FMR Inc | 10.90 | 14,579,166 | -8.3 | 03/31/2026 |
| Capital World Investors | 8.33 | 11,144,846 | +3.2 | 06/30/2026 |
| BlackRock Inc | 7.81 | 10,444,908 | +0.4 | 03/31/2026 |
| Capital Research Global Investors | 7.29 | 9,750,699 | +3.0 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 4.85 | 6,491,280 | +0.0 | 03/31/2026 |
| JPMorgan Chase & Co | 4.73 | 6,323,752 | +34.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 4.44 | 5,946,706 | +0.0 | 03/31/2026 |
| T. Rowe Price Investment Management,Inc. | 3.88 | 5,193,324 | +78.8 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| American Funds Growth Fd of Amer A | 5.70 | 7,620,583 | -5.0 | 06/30/2026 |
| Capital Group Growth Fnd of Amer Comp | 5.70 | 7,620,583 | -5.0 | 06/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.