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 ($162.2m this quarter). Holder counts are more reliable. Shares outstanding: 131.1m as of 2025-07-25, 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 ≈ $326.08. Options: 27 managers hold calls ($198.7m notional), 24 hold puts ($203.8m).
Trends to Q2 2025
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 |
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 2023 | 200 | 224 |
| Q4 2023 | 241 | 204 |
| Q1 2024 | 271 | 213 |
| Q2 2024 | 276 | 223 |
| Q3 2024 | 321 | 228 |
| Q4 2024 | 301 | 242 |
| Q1 2025 | 327 | 271 |
| Q2 2025 | 351 | 278 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2024 | $363.9m | $324.8m | 0.89 |
| Q4 2024 | $195.0m | $166.0m | 0.85 |
| Q1 2025 | $273.8m | $238.4m | 0.87 |
| Q2 2025 | $198.7m | $203.8m | 1.03 |
Biggest buyers
| CITADEL ADVISORS LLC | Added | +597.0k |
| Holocene Advisors, LP | New | +596.8k |
| Clearbridge Investments, LLC | Added | +549.3k |
| MACQUARIE GROUP LTD | Added | +527.5k |
| ROYAL BANK OF CANADA | Added | +524.4k |
| FMR LLC | Added | +496.7k |
| Orbis Allan Gray Ltd | Added | +486.5k |
| Woodline Partners LP | Added | +466.7k |
| Invesco Ltd. | Added | +427.9k |
| BlackRock, Inc. | Added | +420.8k |
Biggest sellers
| AQR CAPITAL MANAGEMENT LLC | Reduced | -640.1k |
| BAILLIE GIFFORD & CO | Reduced | -625.7k |
| WELLINGTON MANAGEMENT GROUP LLP | Reduced | -535.2k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -360.2k |
| Qube Research & Technologies Ltd | Sold out | -330.3k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -197.8k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -196.9k |
| STATE STREET CORP | Reduced | -193.5k |
| D. E. Shaw & Co., Inc. | Reduced | -181.6k |
| Sofinnova Investments, Inc. | Sold out | -176.2k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $66.1m202.8k shares |
| PEAK6 LLC | Added | $21.6m66.2k shares |
| CITADEL ADVISORS LLC | Reduced | $19.7m60.3k shares |
| MILLENNIUM MANAGEMENT LLC | Reduced | $14.7m45.1k shares |
| Twin Tree Management, LP | Reduced | $12.0m36.8k shares |
| GARDA CAPITAL PARTNERS LP | Added | $10.2m31.3k shares |
| JANE STREET GROUP, LLC | Reduced | $8.5m26.1k shares |
| GOLDMAN SACHS GROUP INC | Added | $6.8m20.9k shares |
| WELLS FARGO & COMPANY/MN | Unchanged | $6.5m20.0k shares |
| IMC-Chicago, LLC | Reduced | $5.3m16.2k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $56.6m173.5k shares |
| 683 Capital Management, LLC | Added | $46.1m141.3k shares |
| CITADEL ADVISORS LLC | Reduced | $12.8m39.3k shares |
| Portman Square Capital LLP | Unchanged | $11.7m36.0k shares |
| GARDA CAPITAL PARTNERS LP | Reduced | $9.9m30.5k shares |
| GOLDMAN SACHS GROUP INC | Added | $9.8m30.0k shares |
| Caption Management, LLC | New | $9.8m30.0k shares |
| JANE STREET GROUP, LLC | Reduced | $7.8m24.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $7.3m22.3k shares |
| Twin Tree Management, LP | Reduced | $7.1m21.9k 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 in Q2 2025
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 |
|---|---|---|---|---|---|
| Q3 2023 | 0 | — | 5 | $3.5m | — |
| Q4 2023 | 0 | — | 1 | $5.8m | $5.8m |
| Q1 2024 | 0 | — | 6 | $7.0m | $4.5m |
| Q2 2024 | 0 | — | 7 | $15.5m | $12.4m |
| Q3 2024 | 1 | $9.2k | 3 | $21.4m | $21.4m |
| 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 |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-06-02 | Greenstreet Yvonne Chief Executive Officer, director | Sold plan | $5.9m19.3k shares |
| 2025-05-30 | Greenstreet Yvonne Chief Executive Officer, director | Sold plan | $9.6m31.6k shares |
| 2025-05-15 | BONNEY MICHAEL W Director | Sold plan | $3.1m11.2k shares |
| 2025-04-16 | Reitan Colleen F Director | Sold | $8.4k36 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 2025
| Manager | Shares | Change |
|---|---|---|
| Capital World Investors 0.80% of their portfolio | 16.8m $5.5bn | Added +55.4k |
| FMR LLC 0.29% of their portfolio | 15.8m $5.2bn | Added +496.7k |
| VANGUARD GROUP INC 0.07% of their portfolio | 13.3m $4.3bn | Added +240.5k |
| BlackRock, Inc. 0.06% of their portfolio | 10.0m $3.3bn | Added +420.8k |
| Capital Research Global Investors 0.47% of their portfolio | 7.2m $2.3bn | Added +36.9k |
| REGENERON PHARMACEUTICALS, INC. 97.60% of their portfolio | 4.4m $1.4bn | Unchanged |
| T. Rowe Price Investment Management, Inc. 0.88% of their portfolio | 4.3m $1.4bn | Reduced -136.9k |
| Dodge & Cox 0.59% of their portfolio | 3.2m $1.0bn | Reduced -154.7k |
| STATE STREET CORP 0.04% of their portfolio | 3.2m $1.0bn | Reduced -193.5k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.12% of their portfolio | 3.1m $1.0bn | Reduced -360.2k |
| BAILLIE GIFFORD & CO 0.74% of their portfolio | 3.0m $988.7m | Reduced -625.7k |
| GEODE CAPITAL MANAGEMENT, LLC 0.05% of their portfolio | 2.4m $779.9m | Added +75.9k |
| Orbis Allan Gray Ltd 3.36% of their portfolio | 2.1m $691.8m | Added +486.5k |
| WELLINGTON MANAGEMENT GROUP LLP 0.12% of their portfolio | 2.1m $676.9m | Reduced -535.2k |
| JPMORGAN CHASE & CO 0.05% of their portfolio | 2.1m $672.4m | Reduced -156.9k |
| NORGES BANK 0.08% of their portfolio | 2.0m $662.8m | Reduced -103.3k |
| AMERICAN CENTURY COMPANIES INC 0.32% of their portfolio | 1.8m $585.0m | Added +33.4k |
| GROUPAMA ASSET MANAGMENT 0.03% of their portfolio | 1.5m $1.9m | Unchanged |
| Invesco Ltd. 0.07% of their portfolio | 1.3m $437.5m | Added +427.9k |
| BANK OF AMERICA CORP /DE/ 0.03% of their portfolio | 1.3m $410.0m | Added +192.8k |
| Winslow Capital Management, LLC 1.28% of their portfolio | 1.2m $384.0m | Reduced -9.7k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.06% of their portfolio | 958.3k $312.5m | Added +222.2k |
| Legal & General Group Plc 0.07% of their portfolio | 872.8k $284.6m | Reduced -8.3k |
| ROYAL BANK OF CANADA 0.03% of their portfolio | 861.7k $281.0m | Added +524.4k |
| NORTHERN TRUST CORP 0.04% of their portfolio | 831.8k $271.2m | Reduced -33.2k |
| Nuveen, LLC 0.07% of their portfolio | 775.0k $252.7m | Reduced -108.4k |
| MORGAN STANLEY 0.02% of their portfolio | 771.0k $251.4m | Added +129.2k |
| Bellevue Group AG 4.86% of their portfolio | 676.4k $220.6m | Reduced -91.8k |
| DEUTSCHE BANK AG\ 0.08% of their portfolio | 649.3k $211.7m | Added +72.3k |
| Woodline Partners LP 1.07% of their portfolio | 623.1k $203.2m | Added +466.7k |
| FRANKLIN RESOURCES INC 0.05% of their portfolio | 601.3k $196.1m | Added +143.0k |
| CITADEL ADVISORS LLC 0.17% of their portfolio | 601.2k $196.0m | Added +597.0k |
| MACQUARIE GROUP LTD 0.24% of their portfolio | 600.1k $195.7m | Added +527.5k |
| Holocene Advisors, LP 0.48% of their portfolio | 596.8k $194.6m | New |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.03% of their portfolio | 571.7k $186.4m | Added +25.1k |
| Clearbridge Investments, LLC 0.15% of their portfolio | 557.1k $181.7m | Added +549.3k |
| GOLDMAN SACHS GROUP INC 0.03% of their portfolio | 545.3k $177.8m | Added +121.9k |
| UBS Group AG 0.04% of their portfolio | 543.5k $177.2m | Added +264.8k |
| LOOMIS SAYLES & CO L P 0.20% of their portfolio | 487.3k $158.9m | Reduced -10.2k |
| Pictet Asset Management Holding SA 0.15% of their portfolio | 464.6k $151.2m | Reduced -16.4k |
| TD Asset Management Inc 0.12% of their portfolio | 441.2k $143.9m | Reduced -45.4k |
| Bank of New York Mellon Corp 0.03% of their portfolio | 429.8k $140.1m | Reduced -45.1k |
| Amundi 0.04% of their portfolio | 394.2k $130.0m | Reduced -60.8k |
| Swiss National Bank 0.08% of their portfolio | 393.8k $128.4m | Added +29.6k |
| JENNISON ASSOCIATES LLC 0.07% of their portfolio | 350.1k $114.2m | Added +40.9k |
| TWO SIGMA INVESTMENTS, LP 0.20% of their portfolio | 343.3k $111.9m | Added +145.9k |
| ORBIMED ADVISORS LLC 2.80% of their portfolio | 341.9k $111.5m | Reduced -4.2k |
| GILDER GAGNON HOWE & CO LLC 1.17% of their portfolio | 337.1k $109.9m | Reduced -8.5k |
| FEDERATED HERMES, INC. 0.20% of their portfolio | 323.8k $105.6m | Added +59.7k |
| WELLS FARGO & COMPANY/MN 0.02% of their portfolio | 321.8k $104.9m | Added +21.7k |
| Allspring Global Investments Holdings, LLC 0.17% of their portfolio | 312.2k $100.6m | Added +41.3k |
| SEI INVESTMENTS CO 0.12% of their portfolio | 308.6k $100.6m | Added +31.2k |
| DIMENSIONAL FUND ADVISORS LP 0.02% of their portfolio | 305.6k $99.6m | Reduced -4.3k |
| Sumitomo Mitsui Trust Group, Inc. 0.06% of their portfolio | 293.5k $95.7m | Added +2.1k |
| RAYMOND JAMES FINANCIAL INC 0.03% of their portfolio | 270.4k $88.2m | Added +1.5k |
| TWO SIGMA ADVISERS, LP 0.18% of their portfolio | 266.1k $86.8m | Reduced -9.7k |
| ROYAL LONDON ASSET MANAGEMENT LTD 0.19% of their portfolio | 259.1k $84.5m | Reduced -27.9k |
| FIRST TRUST ADVISORS LP 0.07% of their portfolio | 251.8k $82.1m | Added +71.4k |
| CITIGROUP INC 0.06% of their portfolio | 248.2k $80.9m | Added +53.5k |
| MARSHALL WACE, LLP 0.09% of their portfolio | 238.6k $77.8m | Reduced -30.4k |
| Candriam S.C.A. 0.45% of their portfolio | 238.1k $77.6m | Reduced -11.8k |
| Polar Capital Holdings Plc 0.41% of their portfolio | 237.5k $77.4m | Reduced -42.5k |
| 1832 Asset Management L.P. 0.13% of their portfolio | 223.3k $72.8m | Added +79.3k |
| Aberdeen Group plc 0.12% of their portfolio | 218.6k $70.4m | Added +3.2k |
| CIBC Private Wealth Group LLC 0.13% of their portfolio | 218.3k $71.2m | Added +12.8k |
| California Public Employees Retirement System 0.04% of their portfolio | 211.6k $69.0m | Added +10.1k |
| VOYA INVESTMENT MANAGEMENT LLC 0.07% of their portfolio | 211.0k $68.8m | Added +28.8k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.10% of their portfolio | 208.3k $67.9m | Added +137.8k |
| Allianz Asset Management GmbH 0.09% of their portfolio | 206.0k $67.2m | Reduced -12.5k |
| Point72 Asset Management, L.P. 0.16% of their portfolio | 201.4k $65.7m | Reduced -99.2k |
| RHUMBLINE ADVISERS 0.06% of their portfolio | 200.5k $65.4m | Added +19.0k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.07% of their portfolio | 199.3k $65.0m | Added +1.9k |
| AMERIPRISE FINANCIAL INC 0.02% of their portfolio | 193.6k $63.1m | Added +84.5k |
| KBC Group NV 0.17% of their portfolio | 193.6k $63.1m | Added +174.2k |
| AQR CAPITAL MANAGEMENT LLC 0.05% of their portfolio | 188.2k $61.3m | Reduced -640.1k |
| WESTFIELD CAPITAL MANAGEMENT CO LP 0.26% of their portfolio | 186.9k $60.9m | Reduced -5.3k |
| National Pension Service 0.05% of their portfolio | 175.0k $57.1m | Added +1.4k |
| SCS Capital Management LLC 0.62% of their portfolio | 170.7k $55.7m | Reduced -415 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.04% of their portfolio | 169.7k $55.3m | Added +165.6k |
| VICTORY CAPITAL MANAGEMENT INC 0.03% of their portfolio | 156.3k $51.0m | Added +118.6k |
| Handelsbanken Fonder AB 0.18% of their portfolio | 155.4k $50.7m | Added +38.7k |
| JANUS HENDERSON GROUP PLC 0.02% of their portfolio | 150.4k $49.0m | Reduced -31.2k |
| FIL Ltd 0.04% of their portfolio | 147.9k $48.2m | Added +30.1k |
| DEERFIELD MANAGEMENT COMPANY, L.P. 0.86% of their portfolio | 145.0k $47.3m | Unchanged |
| BNP PARIBAS FINANCIAL MARKETS 0.03% of their portfolio | 128.6k $41.9m | Added +86.1k |
| CAPITAL INTERNATIONAL SARL 0.80% of their portfolio | 128.3k $41.8m | Added +7.1k |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.07% of their portfolio | 127.0k $41.4m | Added +1.8k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.72% of their portfolio | 125.9k $41.1m | Reduced -40.5k |
| ANTIPODES PARTNERS Ltd 1.24% of their portfolio | 122.8k $40.0m | Reduced -36.8k |
| WORLDQUANT MILLENNIUM ADVISORS LLC 0.19% of their portfolio | 117.4k $38.3m | Reduced -73.7k |
| Balyasny Asset Management L.P. 0.09% of their portfolio | 115.3k $37.6m | Added +102.2k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.07% of their portfolio | 114.4k $37.3m | Reduced -3.4k |
| DekaBank Deutsche Girozentrale 0.07% of their portfolio | 113.2k $36.5m | Added +151 |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.03% of their portfolio | 111.8k $36.5m | Added +5.9k |
| Korea Investment CORP 0.08% of their portfolio | 110.9k $36.1m | Added +5.1k |
| HighTower Advisors, LLC 0.04% of their portfolio | 109.3k $35.6m | Reduced -4.6k |
| D. E. Shaw & Co., Inc. 0.04% of their portfolio | 108.3k $35.3m | Reduced -181.6k |
| Soleus Capital Management, L.P. 2.40% of their portfolio | 106.8k $34.8m | New |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.31% of their portfolio | 103.0k $33.6m | Added +583 |
| Ensign Peak Advisors, Inc 0.06% of their portfolio | 100.2k $32.7m | Added +19.7k |