Updated Jul 16, 2026 · Last SEC filing 2026-07-10
INSMED Inc (INSM) has filed 27 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-07-10. 3 Form 8-K material event filings were reported by INSM in the last 90 days. 21 Form 144 notices of proposed sale were filed for INSM stock. InsiderAlpha tracks every INSM SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SEC CIK | 0001104506 |
|---|
| Form 4 filings (90d) | 27 |
|---|---|
| Form 8-K filings (90d) | 3 |
| Form 144 notices (90d) | 21 |
| Latest Form 4 filing | 2026-07-10 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Lewis William | Chair and CEO | S — Open-market sale | 5.0K | $116.55 | $583K | SEC | |
| Lewis William | Chair and CEO | M — Option exercise | 4.4K | $17.16 | $76K | SEC | |
| Lewis William | Chair and CEO | S — Open-market sale | 2.3K | $117.62 | $275K | SEC | |
| Lewis William | Chair and CEO | S — Open-market sale | 3.4K | $118.52 | $398K | SEC | |
| Lewis William | Chair and CEO | M — Option exercise | 6.3K | $30.46 | $191K | SEC | |
| Flammer Martina M.D. | Chief Medical Officer | S — Open-market sale | 4.9K | $109.02 | $529K | SEC | |
| Flammer Martina M.D. | Chief Medical Officer | S — Open-market sale | 7.4K | $110.60 | $824K | SEC | |
| Flammer Martina M.D. | Chief Medical Officer | M — Option exercise | 7.9K | $29.13 | $231K | SEC | |
| Flammer Martina M.D. | Chief Medical Officer | M — Option exercise | 4.4K | $19.74 | $86K | SEC | |
| Lewis William | Chair and CEO | S — Open-market sale | 1.8K | $103.10 | $189K | SEC | |
| Lewis William | Chair and CEO | S — Open-market sale | 1.3K | $106.27 | $137K | SEC | |
| Lewis William | Chair and CEO | S — Open-market sale | 12.1K | $102.34 | $1.24M | SEC | |
| Lewis William | Chair and CEO | M — Option exercise | 8.9K | $17.16 | $152K | SEC | |
| Lewis William | Chair and CEO | S — Open-market sale | 3.7K | $104.28 | $388K | SEC | |
| Lewis William | Chair and CEO | M — Option exercise | 12.5K | $30.46 | $381K | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for INSMED Inc (INSM). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| Lewis William | 44 | $13.73M |
| Flammer Martina M.D. | 15 | $5.78M |
| Smith Michael Alexander | 4 | $1.54M |
| Bonstein Sara | 2 | $1.21M |
| Adsett Roger | 2 | $921K |
Form 144 must be filed before insiders sell restricted or control stock above SEC thresholds. A cluster of Form 144 notices often precedes a wave of insider distribution.
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in INSM insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
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