Insmed Inc
Ownership
Ownership Structure
Who owns Insmed Inc (INSM)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 99.3% of the shares are freely tradable; institutional investors hold 105.7%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| FMR Inc | 7.39 | 16,143,583 | +22.7 | 06/30/2026 |
| BlackRock Inc | 7.24 | 15,807,984 | -5.2 | 06/30/2026 |
| JPMorgan Chase & Co | 4.78 | 10,428,170 | -56.8 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 4.77 | 10,407,962 | +0.3 | 06/30/2026 |
| Vanguard Capital Management, LLC | 4.48 | 9,790,865 | +1.5 | 06/30/2026 |
| Baker Bros Advisors LP | 4.03 | 8,796,111 | +18.5 | 06/30/2026 |
| Capital Research & Mgmt Co - Division 3 | 3.77 | 8,238,124 | +47.2 | 06/30/2026 |
| Darwin Global Management, Ltd. | 2.94 | 6,431,163 | -61.7 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 3.18 | 6,950,044 | +0.8 | 09/30/2026 |
| American Funds Growth Fd of Amer A | 3.09 | 6,750,832 | +7.9 | 09/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Adsett Roger | Chief Operating Officer | 98,744 | 10,861,840 $ | Aug 10, 2026 | direct |
| Flammer Martina M.D. | Chief Medical Officer | 60,486 | 6,653,460 $ | Aug 6, 2026 | direct |
| Brennan David R | Director | 39,238 | 4,316,180 $ | Sep 9, 2026 | direct |
| Hudson Paul | Director | 6,139 | 675,290 $ | Oct 19, 2026 | direct |
| Koppikar Utpal | Director | 6,139 | 675,290 $ | Oct 19, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Oct 19, 2026 | Hudson Paul | Director | Other | 6,139 | – | – |
| Oct 19, 2026 | Koppikar Utpal | Director | Other | 6,139 | – | – |
| Sep 9, 2026 | Brennan David R | Director | Sell | 25,000 | 124.00 | 3,100,000 |
| Aug 17, 2026 | Sharoky Melvin Md | Director | Sell | 5,000 | 127.53 | 637,650 |
| Aug 10, 2026 | Adsett Roger | Chief Operating Officer | Sell | 239,850 | 133.27 | 31,964,810 |
| Aug 10, 2026 | Adsett Roger | Chief Operating Officer | Other | 80,970 | 30.46 | 2,466,346 |
| Aug 10, 2026 | Adsett Roger | Chief Operating Officer | Other | 76,600 | 17.16 | 1,314,456 |
| Aug 10, 2026 | Adsett Roger | Chief Operating Officer | Other | 82,280 | 13.67 | 1,124,768 |
| Aug 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Sell | 18,278 | 129.40 | 2,365,173 |
| Aug 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Sell | 8,895 | 127.00 | 1,129,665 |
| Aug 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Other | 8,895 | 25.83 | 229,758 |
| Aug 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Other | 18,278 | 18.95 | 346,368 |
| Jul 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Sell | 7,448 | 110.60 | 823,749 |
| Jul 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Sell | 4,854 | 109.02 | 529,183 |
| Jul 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Other | 4,357 | 19.74 | 86,007 |
| Jul 6, 2026 | Flammer Martina M.D. | Chief Medical Officer | Other | 7,945 | 29.13 | 231,438 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: November 4, 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.