INSMED INC INSM
COM PAR $.01 · Common Stock · CUSIP 457669307 · ISIN US4576693075
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersBridgewater, NJ
- 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 ($61.1m this quarter). Holder counts are more reliable. Shares outstanding: 216.8m as of 2026-05-01, 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 ≈ $161.60. Options: 23 managers hold calls ($352.2m notional), 22 hold puts ($231.9m).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 239 |
| Q4 2022 | 226 |
| Q1 2023 | 232 |
| Q2 2023 | 225 |
| Q3 2023 | 254 |
| Q4 2023 | 273 |
| Q1 2024 | 290 |
| Q2 2024 | 380 |
| Q3 2024 | 417 |
| Q4 2024 | 441 |
| Q1 2025 | 444 |
| Q2 2025 | 518 |
| Q3 2025 | 566 |
| Q4 2025 | 677 |
| Q1 2026 | 674 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 257 | 137 |
| Q3 2024 | 257 | 152 |
| Q4 2024 | 226 | 188 |
| Q1 2025 | 236 | 195 |
| Q2 2025 | 290 | 242 |
| Q3 2025 | 320 | 264 |
| Q4 2025 | 403 | 263 |
| Q1 2026 | 377 | 307 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $330.0m | $356.0m | 1.08 |
| Q3 2025 | $640.6m | $658.6m | 1.03 |
| Q4 2025 | $673.7m | $741.7m | 1.10 |
| Q1 2026 | $352.2m | $231.9m | 0.66 |
Biggest buyers
| FMR LLC | Added | +3.2m |
| Artisan Partners Limited Partnership | Added | +1.7m |
| BlackRock, Inc. | Added | +1.6m |
| Capital World Investors | New | +1.4m |
| D. E. Shaw & Co., Inc. | Added | +1.3m |
| Paradigm Biocapital Advisors LP | New | +1.3m |
| AMERIPRISE FINANCIAL INC | Added | +1.1m |
| WESTFIELD CAPITAL MANAGEMENT CO LP | Added | +1.0m |
| CITADEL ADVISORS LLC | Added | +1.0m |
| JPMORGAN CHASE & CO | Added | +951.0k |
Biggest sellers
| Darwin Global Management, Ltd. | Reduced | -4.1m |
| Orbis Allan Gray Ltd | Reduced | -2.3m |
| Invesco Ltd. | Reduced | -1.0m |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -946.7k |
| Jefferies Financial Group Inc. | Reduced | -922.8k |
| Holocene Advisors, LP | Sold out | -801.2k |
| TWO SIGMA INVESTMENTS, LP | Reduced | -725.1k |
| TWO SIGMA ADVISERS, LP | Sold out | -395.0k |
| JANUS HENDERSON GROUP PLC | Reduced | -381.3k |
| Duquesne Family Office LLC | Reduced | -327.7k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $81.0m495.3k shares |
| CITADEL ADVISORS LLC | Reduced | $62.1m379.7k shares |
| JANE STREET GROUP, LLC | Reduced | $54.7m334.5k shares |
| CITIGROUP INC | Added | $32.7m200.0k shares |
| Squarepoint Ops LLC | Added | $22.6m138.3k shares |
| MILLENNIUM MANAGEMENT LLC | New | $22.5m137.3k shares |
| JPMORGAN CHASE & CO | Added | $16.1m105.0k shares |
| Eversept Partners, LP | New | $15.4m94.0k shares |
| Caption Management, LLC | Reduced | $7.1m43.2k shares |
| NOMURA HOLDINGS INC | Reduced | $4.9m30.0k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $67.0m410.0k shares |
| Artia Global Partners LP | Reduced | $45.7m279.7k shares |
| JANE STREET GROUP, LLC | Reduced | $17.9m109.7k shares |
| Caption Management, LLC | Reduced | $16.4m100.3k shares |
| Jefferies Financial Group Inc. | Unchanged | $16.3m99.9k shares |
| Parallax Volatility Advisers, L.P. | Unchanged | $14.4m102.3k shares |
| 683 Capital Management, LLC | New | $9.8m60.0k shares |
| CITADEL ADVISORS LLC | Reduced | $8.3m50.8k shares |
| NOMURA HOLDINGS INC | Added | $8.2m50.0k shares |
| Walleye Capital LLC | Added | $4.4m26.8k 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 +1.3 pts · filed 2026-08-06 | 7.4% |
| BlackRock, Inc. 13G · institution +1.5 pts · filed 2026-01-21 | 6.6% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.3% |
Fell to 5% or below in the last year: Darwin Global Management, Ltd. (3.0%, 2026-08-14), JPMORGAN CHASE & CO (4.7%, 2026-07-22), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD CAPITAL MANAGEMENT LLC), PRICE T ROWE ASSOCIATES INC /MD/ (3.3%, 2025-11-14)
Insider purchases and sales in Q1 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 |
|---|---|---|---|---|---|
| Q2 2024 | 0 | — | 7 | $28.7m | $26.9m |
| Q3 2024 | 0 | — | 3 | $25.6m | $18.4m |
| Q4 2024 | 0 | — | 1 | $3.7m | $3.7m |
| Q1 2025 | 0 | — | 7 | $53.0m | $32.1m |
| Q2 2025 | 1 | $201.7k | 7 | $54.6m | $49.9m |
| Q3 2025 | 0 | — | 7 | $65.6m | $57.2m |
| Q4 2025 | 0 | — | 7 | $44.3m | $16.7m |
| Q1 2026 | 0 | — | 6 | $45.2m | $40.6m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-30 | Smith Michael Alexander Chief Legal Officer | Sold plan | $3.0m19.6k shares |
| 2026-03-19 | Lewis William Chair and CEO, director | Sold plan | $1.5m10.7k shares |
| 2026-03-05 | Lewis William Chair and CEO, director | Sold plan | $1.6m10.7k shares |
| 2026-02-24 | Smith Michael Alexander Chief Legal Officer | Sold plan | $3.9m24.8k shares |
| 2026-02-19 | Lewis William Chair and CEO, director | Sold plan | $1.6m10.7k shares |
| 2026-02-09 | Lewis William Chair and CEO, director | Sold plan | $2.0m13.4k shares |
| 2026-02-05 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $132.5k869 shares |
| 2026-02-03 | Lewis William Chair and CEO, director | Sold | $470.4k3.0k shares |
| 2026-02-03 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $123.8k795 shares |
| 2026-02-03 | Adsett Roger Chief Operating Officer | Sold | $123.5k791 shares |
| 2026-02-03 | Bonstein Sara Chief Financial Officer | Sold | $116.9k748 shares |
| 2026-02-03 | Smith Michael Alexander Chief Legal Officer | Sold | $100.0k640 shares |
| 2026-02-02 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $1.2m8.0k shares |
| 2026-01-20 | Lewis William Chair and CEO, director | Sold plan | $1.7m10.7k shares |
| 2026-01-12 | Lewis William Chair and CEO, director | Sold plan | $3.2m19.2k shares |
| 2026-01-09 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $351.3k1.9k shares |
| 2026-01-08 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $854.9k4.9k shares |
| 2026-01-08 | Lewis William Chair and CEO, director | Sold | $561.3k3.2k shares |
| 2026-01-08 | Adsett Roger Chief Operating Officer | Sold | $358.6k2.1k shares |
| 2026-01-08 | Bonstein Sara Chief Financial Officer | Sold | $252.0k1.4k shares |
| 2026-01-08 | Smith Michael Alexander Chief Legal Officer | Sold | $183.4k1.1k shares |
| 2026-01-07 | Lewis William Chair and CEO, director | Sold | $412.6k2.4k shares |
| 2026-01-07 | Bonstein Sara Chief Financial Officer | Sold | $293.8k1.7k shares |
| 2026-01-07 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $252.2k1.4k shares |
| 2026-01-07 | Adsett Roger Chief Operating Officer | Sold | $140.4k802 shares |
| 2026-01-07 | Smith Michael Alexander Chief Legal Officer | Sold | $124.1k709 shares |
| 2026-01-06 | Flammer Martina M.D. Chief Medical Officer | Sold plan | $1.8m10.2k shares |
| 2026-01-06 | Lewis William Chair and CEO, director | Sold | $710.0k4.1k shares |
| 2026-01-06 | Bonstein Sara Chief Financial Officer | Sold | $262.9k1.5k shares |
| 2026-01-06 | Adsett Roger Chief Operating Officer | Sold | $247.7k1.4k shares |
The latest 30 of 33 trades.
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, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| JPMORGAN CHASE & CO 0.25% of their portfolio | 24.2m $3.7bn | Added +951.0k |
| Darwin Global Management, Ltd. 68.33% of their portfolio | 16.8m $2.6bn | Reduced -4.1m |
| BlackRock, Inc. 0.05% of their portfolio | 16.7m $2.7bn | Added +1.6m |
| FMR LLC 0.11% of their portfolio | 13.2m $2.2bn | Added +3.2m |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.09% of their portfolio | 10.4m $1.7bn | First filing |
| VANGUARD CAPITAL MANAGEMENT LLC 0.04% of their portfolio | 9.6m $1.6bn | First filing |
| BAKER BROS. ADVISORS LP 6.97% of their portfolio | 7.4m $1.2bn | Added +828.4k |
| Artisan Partners Limited Partnership 1.74% of their portfolio | 6.5m $1.1bn | Added +1.7m |
| Invesco Ltd. 0.10% of their portfolio | 6.5m $1.1bn | Reduced -1.0m |
| D. E. Shaw & Co., Inc. 0.72% of their portfolio | 5.6m $919.9m | Added +1.3m |
| Capital International Investors 0.21% of their portfolio | 5.6m $914.9m | Added +443.5k |
| STATE STREET CORP 0.03% of their portfolio | 5.6m $907.8m | Added +350.0k |
| RTW INVESTMENTS, LP 7.88% of their portfolio | 4.8m $791.9m | Added +1 |
| GEODE CAPITAL MANAGEMENT, LLC 0.05% of their portfolio | 4.5m $733.3m | Added +151.3k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.06% of their portfolio | 3.1m $505.7m | Reduced -946.7k |
| AMERIPRISE FINANCIAL INC 0.12% of their portfolio | 3.1m $500.0m | Added +1.1m |
| FRANKLIN RESOURCES INC 0.10% of their portfolio | 2.6m $428.0m | Reduced -138.3k |
| CITADEL ADVISORS LLC 0.25% of their portfolio | 2.2m $356.9m | Added +1.0m |
| NWI MANAGEMENT LP 10.14% of their portfolio | 2.0m $331.6m | Added +51.1k |
| Orbis Allan Gray Ltd 1.29% of their portfolio | 1.9m $306.2m | Reduced -2.3m |
| UBS Group AG 0.05% of their portfolio | 1.7m $284.1m | Reduced -130.2k |
| BANK OF AMERICA CORP /DE/ 0.02% of their portfolio | 1.5m $245.7m | Reduced -223.4k |
| Integral Health Asset Management, LLC 12.98% of their portfolio | 1.5m $245.3m | Added +250.0k |
| WESTFIELD CAPITAL MANAGEMENT CO LP 1.01% of their portfolio | 1.5m $240.1m | Added +1.0m |
| SEI INVESTMENTS CO 0.21% of their portfolio | 1.4m $228.2m | Added +505.6k |
| Capital World Investors 0.03% of their portfolio | 1.4m $222.7m | New |
| VANGUARD FIDUCIARY TRUST CO 0.06% of their portfolio | 1.4m $221.5m | First filing |
| MORGAN STANLEY 0.01% of their portfolio | 1.3m $217.7m | Reduced -300.4k |
| NORTHERN TRUST CORP 0.03% of their portfolio | 1.3m $211.6m | Added +55.6k |
| Castle Hook Partners LP 4.20% of their portfolio | 1.3m $207.6m | Added +16.2k |
| Bank of New York Mellon Corp 0.04% of their portfolio | 1.3m $206.5m | Reduced -127.3k |
| Paradigm Biocapital Advisors LP 4.19% of their portfolio | 1.3m $205.1m | New |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.04% of their portfolio | 1.2m $198.7m | Added +271.7k |
| MILLENNIUM MANAGEMENT LLC 0.14% of their portfolio | 1.2m $189.3m | Reduced -153.9k |
| Duquesne Family Office LLC 6.43% of their portfolio | 1.2m $188.7m | Reduced -327.7k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.32% of their portfolio | 1.1m $187.0m | Reduced -39.3k |
| Pictet Asset Management Holding SA 0.19% of their portfolio | 1.1m $178.7m | Added +143.3k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.03% of their portfolio | 1.1m $174.9m | Added +42.0k |
| Fiera Capital Corp 0.57% of their portfolio | 1.0m $167.1m | Added +29.1k |
| GOLDMAN SACHS GROUP INC 0.02% of their portfolio | 942.6k $154.1m | Reduced -302.3k |
| AMERICAN CENTURY COMPANIES INC 0.08% of their portfolio | 925.8k $151.4m | Added +740.7k |
| PRINCIPAL FINANCIAL GROUP INC 0.08% of their portfolio | 916.5k $149.9m | Added +145.1k |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC 0.49% of their portfolio | 902.7k $147.6m | Reduced -318.4k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.23% of their portfolio | 900.0k $147.2m | Added +600.0k |
| FIL Ltd 0.11% of their portfolio | 828.9k $135.5m | Reduced -9.6k |
| Amundi 0.04% of their portfolio | 805.0k $131.6m | Reduced -112.0k |
| Legal & General Group Plc 0.03% of their portfolio | 787.1k $128.7m | Added +246.8k |
| RAYMOND JAMES FINANCIAL INC 0.04% of their portfolio | 775.1k $121.4m | Reduced -4.1k |
| ALLIANCEBERNSTEIN L.P. 0.04% of their portfolio | 688.7k $119.9m | Added +46.0k |
| Hood River Capital Management LLC 1.13% of their portfolio | 688.6k $112.6m | Added +51.0k |
| AQR CAPITAL MANAGEMENT LLC 0.05% of their portfolio | 675.5k $108.8m | Added +207.2k |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC 4.94% of their portfolio | 653.4k $106.9m | Reduced -255.6k |
| Clearbridge Investments, LLC 0.09% of their portfolio | 643.4k $105.2m | Reduced -175.6k |
| Artia Global Partners LP 23.18% of their portfolio | 628.7k $102.8m | Reduced -53.5k |
| Swiss National Bank 0.06% of their portfolio | 625.9k $102.3m | Added +46.8k |
| GW&K Investment Management, LLC 0.90% of their portfolio | 623.0k $101.9m | Added +140.4k |
| JENNISON ASSOCIATES LLC 0.07% of their portfolio | 604.7k $98.9m | Added +42.4k |
| BNP PARIBAS FINANCIAL MARKETS 0.07% of their portfolio | 604.6k $98.9m | Reduced -310.8k |
| WELLS FARGO & COMPANY/MN 0.02% of their portfolio | 597.4k $97.7m | Added +10.7k |
| TimesSquare Capital Management, LLC 1.62% of their portfolio | 584.8k $95.6m | Added +94.3k |
| DEUTSCHE BANK AG\ 0.03% of their portfolio | 562.5k $92.0m | Reduced -27.6k |
| EVENTIDE ASSET MANAGEMENT, LLC 1.48% of their portfolio | 546.3k $89.3m | Added +62.7k |
| FEDERATED HERMES, INC. 0.14% of their portfolio | 538.3k $88.0m | Reduced -94.0k |
| Nuveen, LLC 0.02% of their portfolio | 534.8k $87.4m | Reduced -115.7k |
| ROYAL BANK OF CANADA 0.02% of their portfolio | 523.1k $85.5m | Added +16.3k |
| Sumitomo Mitsui Trust Group, Inc. 0.05% of their portfolio | 501.3k $82.0m | Added +65.8k |
| Ensign Peak Advisors, Inc 0.15% of their portfolio | 499.8k $81.7m | Added +117.6k |
| Affinity Asset Advisors, LLC 4.60% of their portfolio | 480.0k $78.5m | Added +30.0k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.79% of their portfolio | 469.6k $76.8m | Added +184.7k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.09% of their portfolio | 467.8k $76.5m | Added +139.4k |
| JANUS HENDERSON GROUP PLC 0.03% of their portfolio | 419.3k $68.6m | Reduced -381.3k |
| SAMLYN CAPITAL, LLC 1.17% of their portfolio | 417.2k $68.2m | Added +47.6k |
| Palo Alto Investors LP 10.39% of their portfolio | 415.3k $67.9m | Reduced -74.2k |
| Candriam S.C.A. 0.34% of their portfolio | 401.7k $65.7m | Added +693 |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 400.9k $65.5m | Added +1.8k |
| WELLINGTON MANAGEMENT GROUP LLP 0.01% of their portfolio | 399.0k $65.3m | Reduced -87.1k |
| LORD, ABBETT & CO. LLC 0.21% of their portfolio | 397.3k $65.0m | Reduced -323.6k |
| VICTORY CAPITAL MANAGEMENT INC 0.04% of their portfolio | 396.2k $64.8m | Reduced -250.5k |
| Polar Capital Holdings Plc 0.26% of their portfolio | 368.1k $60.2m | Added +23.9k |
| GATEWAY INVESTMENT ADVISERS LLC 0.67% of their portfolio | 365.0k $59.7m | Unchanged |
| VANGUARD ASSET MANAGEMENT, Ltd 0.05% of their portfolio | 360.1k $58.9m | First filing |
| Sofinnova Investments, Inc. 2.84% of their portfolio | 346.1k $56.6m | Added +189.3k |
| California Public Employees Retirement System 0.03% of their portfolio | 344.6k $56.4m | Reduced -10.3k |
| Rock Springs Capital Management LP 3.03% of their portfolio | 314.3k $51.4m | Reduced -5.0k |
| MARSHALL WACE, LLP 0.05% of their portfolio | 312.6k $51.1m | Reduced -77.3k |
| National Pension Service 0.04% of their portfolio | 311.9k $51.0m | Added +31.4k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.05% of their portfolio | 303.2k $49.6m | Reduced -7.1k |
| Nearwater Capital Markets, Ltd 1.16% of their portfolio | 300.0k $49.1m | Reduced -200.0k |
| ENVESTNET ASSET MANAGEMENT INC 0.01% of their portfolio | 299.9k $49.0m | Added +23.8k |
| Bridgewater Associates, LP 0.22% of their portfolio | 295.6k $48.3m | New |
| NEW YORK STATE COMMON RETIREMENT FUND 0.07% of their portfolio | 293.5k $48.0m | Added +17.3k |
| ProShare Advisors LLC 0.07% of their portfolio | 283.1k $46.3m | Reduced -57.6k |
| Allspring Global Investments Holdings, LLC 0.08% of their portfolio | 282.7k $46.6m | Added +62.6k |
| Aberdeen Group plc 0.07% of their portfolio | 277.0k $45.3m | Added +23.9k |
| BARCLAYS PLC 0.02% of their portfolio | 275.7k $45.1m | Reduced -169.0k |
| RHUMBLINE ADVISERS 0.04% of their portfolio | 272.6k $44.6m | Added +4.3k |
| NEUBERGER BERMAN GROUP LLC 0.03% of their portfolio | 270.7k $44.3m | Added +62.8k |
| TANG CAPITAL MANAGEMENT LLC 2.16% of their portfolio | 260.0k $42.5m | Added +200.0k |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.03% of their portfolio | 255.2k $41.7m | Added +33.0k |
| First Turn Management, LLC 4.54% of their portfolio | 248.5k $40.6m | Reduced -15.8k |