ALNYLAM PHARMACEUTICALS INC ALNY
COM · Common Stock · CUSIP 02043Q107 · ISIN US02043Q1076
Biopharmaceutical company
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersCambridge, MA
- Founded2002
- Websitealnylam.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($84.8m this quarter). Holder counts are more reliable. Shares outstanding: 133.8m as of 2026-07-24, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $300.86. Options: 23 managers hold calls ($453.4m notional), 20 hold puts ($212.9m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 497 |
| Q4 2022 | 488 |
| Q1 2023 | 478 |
| Q2 2023 | 478 |
| Q3 2023 | 454 |
| Q4 2023 | 501 |
| Q1 2024 | 499 |
| Q2 2024 | 525 |
| Q3 2024 | 570 |
| Q4 2024 | 596 |
| Q1 2025 | 628 |
| Q2 2025 | 655 |
| Q3 2025 | 824 |
| Q4 2025 | 852 |
| Q1 2026 | 793 |
| Q2 2026 | 789 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 321 | 228 |
| Q4 2024 | 301 | 242 |
| Q1 2025 | 327 | 271 |
| Q2 2025 | 351 | 278 |
| Q3 2025 | 497 | 269 |
| Q4 2025 | 410 | 409 |
| Q1 2026 | 411 | 415 |
| Q2 2026 | 403 | 359 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $586.5m | $650.3m | 1.11 |
| Q4 2025 | $744.0m | $493.6m | 0.66 |
| Q1 2026 | $450.2m | $204.8m | 0.45 |
| Q2 2026 | $453.4m | $212.9m | 0.47 |
Biggest buyers
| Deep Track Capital, LP | New | +825.0k |
| Orbis Allan Gray Ltd | Added | +652.6k |
| LOS ANGELES CAPITAL MANAGEMENT LLC | Added | +641.4k |
| Paradigm Biocapital Advisors LP | New | +480.0k |
| BlackRock, Inc. | Added | +462.8k |
| T. Rowe Price Investment Management, Inc. | Added | +448.8k |
| FMR LLC | Added | +444.8k |
| Capital World Investors | Added | +342.5k |
| Capital Research Global Investors | Added | +279.5k |
| STATE STREET CORP | Added | +233.0k |
Biggest sellers
| JPMORGAN CHASE & CO | Reduced | -3.6m |
| MARSHALL WACE, LLP | Reduced | -839.5k |
| Invesco Ltd. | Reduced | -320.8k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -283.5k |
| Allspring Global Investments Holdings, LLC | Reduced | -279.2k |
| Bellevue Group AG | Reduced | -233.5k |
| Squarepoint Ops LLC | Reduced | -192.7k |
| AQR CAPITAL MANAGEMENT LLC | Reduced | -185.1k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | Reduced | -184.7k |
| JACOBS LEVY EQUITY MANAGEMENT, INC | Reduced | -151.2k |
Biggest calls
| D. E. Shaw & Co., Inc. | Added | $129.5m430.3k shares |
| WELLS FARGO & COMPANY/MN | Unchanged | $111.4m370.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $97.8m324.9k shares |
| CITADEL ADVISORS LLC | Added | $24.6m81.6k shares |
| MILLENNIUM MANAGEMENT LLC | Added | $12.9m43.0k shares |
| JANE STREET GROUP, LLC | Added | $12.7m42.1k shares |
| Caption Management, LLC | Added | $12.0m40.0k shares |
| IMC-Chicago, LLC | Added | $11.4m38.0k shares |
| CITIGROUP INC | Added | $7.2m23.9k shares |
| Squarepoint Ops LLC | Reduced | $7.2m23.9k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $53.8m178.8k shares |
| HSBC HOLDINGS PLC | Added | $35.8m120.6k shares |
| 683 Capital Management, LLC | Reduced | $32.4m107.5k shares |
| Portman Square Capital LLP | Added | $13.9m46.2k shares |
| CITADEL ADVISORS LLC | Added | $12.8m42.5k shares |
| CITIGROUP INC | Added | $9.0m29.9k shares |
| IMC-Chicago, LLC | Added | $8.2m27.4k shares |
| JANE STREET GROUP, LLC | Reduced | $6.5m21.7k shares |
| Alphadyne Asset Management LP | New | $6.3m21.0k shares |
| MILLENNIUM MANAGEMENT LLC | Reduced | $6.1m20.2k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution -1.8 pts · filed 2026-05-06 | 11.0% |
| Capital World Investors 13G · institution filed 2026-05-14 | 8.2% |
| Capital Research Global Investors 13G · institution +1.7 pts · filed 2026-05-14 | 7.1% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 5.3% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-26; now reported by VANGUARD CAPITAL MANAGEMENT LLC)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 1 | $1.2k | 5 | $2.9m | $1.2m |
| Q1 2025 | 0 | — | 7 | $29.1m | $25.8m |
| Q2 2025 | 0 | — | 3 | $18.7m | $18.7m |
| Q3 2025 | 0 | — | 8 | $34.3m | $29.4m |
| Q4 2025 | 0 | — | 5 | $27.3m | $19.8m |
| Q1 2026 | 0 | — | 5 | $20.4m | $7.1m |
| Q2 2026 | 0 | — | 2 | $2.4m | $2.4m |
| Q3 2026 | 0 | — | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-06-01 | PYOTT DAVID E I Director | Sold plan | $1.1m3.8k shares |
| 2026-04-06 | McLaughlin Melissa Chief Human Resources Officer | Sold plan | $755.3k2.3k shares |
| 2026-04-02 | McLaughlin Melissa Chief Human Resources Officer | Sold plan | $519.0k1.6k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.20% of their portfolio | 15.0m $4.5bn | Added +444.8k |
| Capital World Investors 0.40% of their portfolio | 11.1m $3.4bn | Added +342.5k |
| BlackRock, Inc. 0.05% of their portfolio | 10.9m $3.3bn | Added +462.8k |
| Capital Research Global Investors 0.41% of their portfolio | 9.8m $2.9bn | Added +279.5k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.09% of their portfolio | 6.5m $2.0bn | Added +47.1k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.04% of their portfolio | 6.0m $1.8bn | Added +82.8k |
| T. Rowe Price Investment Management, Inc. 1.11% of their portfolio | 5.6m $1.7bn | Added +448.8k |
| Invesco Ltd. 0.09% of their portfolio | 3.8m $1.1bn | Reduced -320.8k |
| STATE STREET CORP 0.03% of their portfolio | 3.6m $1.1bn | Added +233.0k |
| JPMORGAN CHASE & CO 0.05% of their portfolio | 2.7m $785.3m | Reduced -3.6m |
| GEODE CAPITAL MANAGEMENT, LLC 0.04% of their portfolio | 2.6m $791.3m | Reduced -24.5k |
| BAILLIE GIFFORD & CO 0.67% of their portfolio | 2.4m $734.5m | Reduced -54.0k |
| NORGES BANK 0.07% of their portfolio | 2.3m $683.9m | Not comparable |
| WELLINGTON MANAGEMENT GROUP LLP 0.11% of their portfolio | 2.1m $635.3m | Added +174.5k |
| Orbis Allan Gray Ltd 2.06% of their portfolio | 2.0m $598.3m | Added +652.6k |
| Dodge & Cox 0.31% of their portfolio | 2.0m $588.6m | Added +26.1k |
| TWO SIGMA INVESTMENTS, LP 0.42% of their portfolio | 1.9m $564.7m | Reduced -116.6k |
| AMERICAN CENTURY COMPANIES INC 0.25% of their portfolio | 1.9m $558.1m | Added +51.6k |
| Clearbridge Investments, LLC 0.31% of their portfolio | 1.3m $379.1m | Reduced -96.6k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.03% of their portfolio | 1.1m $345.9m | Reduced -283.5k |
| D. E. Shaw & Co., Inc. 0.21% of their portfolio | 1.1m $332.4m | Added +45.0k |
| MORGAN STANLEY 0.02% of their portfolio | 1.0m $310.7m | Added +29.5k |
| BANK OF AMERICA CORP /DE/ 0.02% of their portfolio | 994.5k $299.4m | Added +27.6k |
| Legal & General Group Plc 0.06% of their portfolio | 924.6k $278.3m | Reduced -10.3k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.21% of their portfolio | 893.8k $269.1m | Added +231.4k |
| NORTHERN TRUST CORP 0.03% of their portfolio | 886.9k $267.0m | Added +28.8k |
| ROYAL BANK OF CANADA 0.04% of their portfolio | 875.9k $263.7m | Added +84.3k |
| VANGUARD FIDUCIARY TRUST CO 0.06% of their portfolio | 862.8k $259.7m | Added +21.9k |
| Deep Track Capital, LP 3.66% of their portfolio | 825.0k $248.3m | New |
| DEUTSCHE BANK AG\ 0.07% of their portfolio | 815.4k $245.5m | Added +53.9k |
| Qube Research & Technologies Ltd 0.27% of their portfolio | 798.7k $240.4m | Reduced -39.5k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.03% of their portfolio | 755.4k $227.4m | Added +82.0k |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.81% of their portfolio | 729.6k $219.6m | Added +641.4k |
| AQR CAPITAL MANAGEMENT LLC 0.08% of their portfolio | 728.0k $219.0m | Reduced -185.1k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.04% of their portfolio | 727.8k $219.1m | Added +50.3k |
| FEDERATED HERMES, INC. 0.31% of their portfolio | 719.9k $216.7m | Added +32.1k |
| UBS Group AG 0.03% of their portfolio | 627.0k $188.7m | Added +168.1k |
| Amundi 0.04% of their portfolio | 617.5k $185.9m | Reduced -130.1k |
| LOOMIS SAYLES & CO L P 0.22% of their portfolio | 580.2k $174.7m | Added +68.1k |
| GOLDMAN SACHS GROUP INC 0.02% of their portfolio | 574.8k $173.0m | Added +105.4k |
| Bank of New York Mellon Corp 0.02% of their portfolio | 492.1k $148.1m | Added +871 |
| Polar Capital Holdings Plc 0.41% of their portfolio | 482.8k $145.3m | Added +225.1k |
| Paradigm Biocapital Advisors LP 2.71% of their portfolio | 480.0k $144.5m | New |
| FRANKLIN RESOURCES INC 0.03% of their portfolio | 447.7k $134.8m | Reduced -22.7k |
| FIRST TRUST ADVISORS LP 0.07% of their portfolio | 421.5k $126.9m | Added +38.8k |
| RAYMOND JAMES FINANCIAL INC 0.03% of their portfolio | 392.8k $118.2m | Reduced -14.2k |
| DIMENSIONAL FUND ADVISORS LP 0.02% of their portfolio | 392.0k $118.0m | Added +7.8k |
| Swiss National Bank 0.06% of their portfolio | 374.1k $112.6m | Reduced -13.6k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.03% of their portfolio | 350.6k $105.5m | Reduced -145.4k |
| CANADA PENSION PLAN INVESTMENT BOARD 0.06% of their portfolio | 334.2k $100.6m | Added +125.3k |
| Sumitomo Mitsui Trust Group, Inc. 0.06% of their portfolio | 325.4k $97.9m | Added +11.0k |
| MILLENNIUM MANAGEMENT LLC 0.06% of their portfolio | 316.0k $95.1m | Reduced -131.9k |
| Nuveen, LLC 0.02% of their portfolio | 315.6k $95.0m | Reduced -6.6k |
| Candriam S.C.A. 0.43% of their portfolio | 314.5k $94.6m | Added +90.2k |
| Assenagon Asset Management S.A. 0.06% of their portfolio | 311.4k $93.7m | Added +182.5k |
| WELLS FARGO & COMPANY/MN 0.02% of their portfolio | 310.0k $93.3m | Reduced -32.7k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.14% of their portfolio | 300.2k $90.4m | Added +41.3k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.08% of their portfolio | 294.5k $88.6m | Added +120.2k |
| Pictet Asset Management Holding SA 0.08% of their portfolio | 278.6k $83.3m | Added +40.7k |
| BNP PARIBAS FINANCIAL MARKETS 0.04% of their portfolio | 271.0k $81.6m | Reduced -9.9k |
| GILDER GAGNON HOWE & CO LLC 0.84% of their portfolio | 269.1k $81.0m | Reduced -11.0k |
| CONGRESS ASSET MANAGEMENT CO 0.49% of their portfolio | 265.7k $80.0m | Reduced -20.0k |
| MARSHALL WACE, LLP 0.07% of their portfolio | 259.8k $78.2m | Reduced -839.5k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.05% of their portfolio | 257.7k $77.6m | Added +38.5k |
| California Public Employees Retirement System 0.04% of their portfolio | 254.1k $76.5m | Added +26.1k |
| WESTFIELD CAPITAL MANAGEMENT CO LP 0.25% of their portfolio | 252.4k $76.0m | Added +6.8k |
| Korea Investment CORP 0.14% of their portfolio | 247.7k $74.6m | Added +47.3k |
| Woodline Partners LP 0.23% of their portfolio | 246.3k $74.1m | Added +2.4k |
| Squarepoint Ops LLC 0.14% of their portfolio | 234.0k $70.4m | Reduced -192.7k |
| TD Asset Management Inc 0.06% of their portfolio | 233.7k $70.3m | Reduced -48.2k |
| CITIGROUP INC 0.03% of their portfolio | 227.8k $68.6m | Reduced -35.6k |
| ROYAL LONDON ASSET MANAGEMENT LTD 0.12% of their portfolio | 213.6k $64.3m | Reduced -1.5k |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 204.6k $61.6m | Reduced -35.3k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.06% of their portfolio | 199.9k $60.2m | Added +3.0k |
| National Pension Service 0.04% of their portfolio | 198.3k $59.7m | Added +14.5k |
| PINEBRIDGE INVESTMENTS LLC 0.49% of their portfolio | 195.7k $58.9m | Reduced -75.7k |
| CITADEL ADVISORS LLC 0.03% of their portfolio | 191.0k $57.5m | Added +167.6k |
| Robeco Institutional Asset Management B.V. 0.07% of their portfolio | 188.1k $56.6m | Added +61.6k |
| VICTORY CAPITAL MANAGEMENT INC 0.03% of their portfolio | 172.8k $52.0m | Reduced -23.1k |
| Man Group plc 0.09% of their portfolio | 170.9k $51.4m | Reduced -61.5k |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.03% of their portfolio | 168.7k $50.8m | Added +16.5k |
| RHUMBLINE ADVISERS 0.04% of their portfolio | 165.6k $49.8m | Reduced -29.7k |
| Life Cycle Investment Partners Ltd 0.23% of their portfolio | 165.4k $49.8m | Reduced -12.1k |
| CIBC Bancorp USA Inc. 0.06% of their portfolio | 163.7k $49.3m | Reduced -5.3k |
| ANTIPODES PARTNERS Ltd 0.90% of their portfolio | 163.5k $49.2m | Added +18.2k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.05% of their portfolio | 161.8k $48.6m | Reduced -18.2k |
| Russell Investments Group, Ltd. 0.04% of their portfolio | 158.2k $47.5m | Added +10.7k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.07% of their portfolio | 157.2k $47.2m | Added +17.5k |
| CAPITAL FUND MANAGEMENT S.A. 0.34% of their portfolio | 155.9k $46.9m | Added +15.8k |
| Vinva Investment Management Ltd 0.30% of their portfolio | 155.0k $45.5m | Added +118.4k |
| Hudson Bay Capital Management LP 0.21% of their portfolio | 148.7k $44.8m | Added +108.7k |
| ENVESTNET ASSET MANAGEMENT INC 0.01% of their portfolio | 136.4k $41.1m | Reduced -35.4k |
| Jupiter Topco LLC 0.02% of their portfolio | 135.5k $40.8m | First filing |
| BARCLAYS PLC 0.01% of their portfolio | 135.5k $40.8m | Reduced -85.1k |
| LMR Partners LLP 0.30% of their portfolio | 134.2k $40.4m | Added +59.6k |
| ProShare Advisors LLC 0.06% of their portfolio | 128.5k $38.7m | Reduced -45.5k |
| SEI INVESTMENTS CO 0.03% of their portfolio | 122.0k $36.7m | Added +21.6k |
| VOYA INVESTMENT MANAGEMENT LLC 0.03% of their portfolio | 121.9k $36.7m | Reduced -26.6k |
| SCS Capital Management LLC 0.33% of their portfolio | 115.5k $34.8m | Reduced -34.0k |
| HSBC HOLDINGS PLC 0.02% of their portfolio | 115.3k $34.6m | Added +25.7k |