Insmed Incorporated
Insmed Incorporated (INSM) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · INSM · as of Sep 30, 2024
Ownership Breakdown
457
Institutional Holders
▲ 20 vs Q2
$13.73B
Total Inst. Value
▲ $1.99B vs Q2
216.75M
Shares Outstanding
freeFloat 91.48%
188.46M
13F Shares Held
▲ 13.22M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
INSM largest shareholders · institutional ownership
Q3 2024 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC pharmaceutical preparations | 17.14M | 9.87% | 9.87% | $1.25T | Nov 13, 2024 | ▲ 1.13M |
BLACKROCK, INC. pharmaceutical preparations | 14.97M | 8.62% | 8.62% | $1.09T | Nov 13, 2024 | NEW |
PRICE T ROWE ASSOCIATES INC /MD/ pharmaceutical preparations | 12.58M | 7.24% | 7.24% | $918.41B | Nov 14, 2024 | ▲ 417.6K |
DARWIN GLOBAL MANAGEMENT, LTD. pharmaceutical preparations | 10.50M | 6.04% | 6.04% | $766.30B | Nov 14, 2024 | ▲ 6.96M |
FMR LLC pharmaceutical preparations | 7.19M | 4.14% | 4.14% | $524.98B | Nov 13, 2024 | ▼ 113.6K |
CAPITAL INTERNATIONAL INVESTORS pharmaceutical preparations | 6.52M | 3.76% | 3.76% | $476.24B | Nov 13, 2024 | ▲ 653.9K |
STATE STREET CORP pharmaceutical preparations | 6.18M | 3.56% | 3.56% | $451.01B | Nov 14, 2024 | ▲ 1.52M |
BAKER BROS. ADVISORS LP pharmaceutical preparations | 4.42M | 2.54% | 2.54% | $322.36B | Nov 14, 2024 | ▲ 839.9K |
GEODE CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 3.81M | 2.20% | 2.20% | $278.43B | Nov 12, 2024 | ▲ 172.7K |
JPMORGAN CHASE & CO pharmaceutical preparations | 3.31M | 1.90% | 1.90% | $241.36B | Dec 26, 2024 | ▲ 380.2K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2024 vs prior quarter
Q3 2024
31
Increased
+19.48M shares2
New Positions
first time holders17
Decreased
−5.54M shares0
Sold Out
fully exitedNet shares change (top 50)
+13.94M
+19.48M / −5.54M
Net new holders
+16
2 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
INSM insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
16
Buy transactions
45
Sell transactions
0.36
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Adsett Roger Chief Operating Officer | Jun 3, 2026 | Sale | 2,370 | $102.27 | $242.4K | 98.6K | Form 4 ↗ |
Bonstein Sara Chief Financial Officer | Jun 3, 2026 | Sale | 2,404 | $102.27 | $245.9K | 69.1K | Form 4 ↗ |
Smith Michael Alexander Chief Legal Officer | Jun 3, 2026 | Sale | 2,159 | $102.27 | $220.8K | 39.5K | Form 4 ↗ |
Lewis William Chair and CEO | Jun 3, 2026 | Sale | 7,605 | $102.27 | $777.8K | 265.4K | Form 4 ↗ |
Flammer Martina M.D. Chief Medical Officer | Jun 3, 2026 | Sale | 2,566 | $102.27 | $262.4K | 62.3K | Form 4 ↗ |
Flammer Martina M.D. Chief Medical Officer | Jun 5, 2026 | Sale | 1,858 | $103.78 | $192.8K | 60.5K | Form 4 ↗ |
Smith Michael Alexander Chief Legal Officer | May 22, 2026 | Sale | 6,149 | $108.47 | $667.0K | 41.6K | Form 4 ↗ |
Lewis William Chair and CEO | May 18, 2026 | Sale | 5,753 | $105.32 | $605.9K | 292.8K | Form 4 ↗ |
Lewis William Chair and CEO | May 18, 2026 | Sale | 11,836 | $106.39 | $1.26M | 281.0K | Form 4 ↗ |
Lewis William Chair and CEO | May 18, 2026 | Sale | 7,975 | $106.97 | $853.1K | 273.0K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Insmed Incorporated (INSM) is primarily owned by institutional investors, who hold approximately 87.0% of total shares outstanding. Company insiders own approximately 8.52%, while retail and public investors account for the remaining 4.54%.
The largest institutional shareholder of Insmed Incorporated is VANGUARD GROUP INC, holding approximately 17.14 million shares — equal to 9.87% of outstanding shares — as of September 30, 2024.
A total of 457 institutional investors currently hold INSM stock, with a combined institutional value of approximately $13.73 billion as of the most recent 13F filing period.
Frequently asked questions
INSM ownershipInsmed Incorporated (INSM) is primarily owned by institutional investors, who hold approximately 87.0% of shares. The largest shareholder is VANGUARD GROUP INC with a 9.87% stake. Company insiders hold 8.52%. Data sourced from SEC Form 13F as of September 30, 2024.