Insmed (INSM) CEO sells 10,699 shares and exercises options under 10b5-1 plan
Filing Impact
Filing Sentiment
Form Type
4
Rhea-AI Filing Summary
Insmed Inc Chair and CEO William Lewis reported a series of routine equity transactions in the company’s common stock. On May 4, 2026, he sold 10,699 shares in multiple open-market trades at weighted average prices ranging from about $134 to $139.60 per share, executed under a Rule 10b5-1 trading plan adopted on September 4, 2025.
On the same date, he exercised stock options to acquire a total of 10,699 shares of common stock at exercise prices of $17.16 and $30.46 per share. The filing also reflects an indirect holding of 233,924 shares held by trust, indicating Lewis continues to maintain a significant ownership position in Insmed alongside these transactions.
Positive
- None.
Negative
- None.
Insider Trade Summary 10b5-1
Net Seller: 10,699 shares ($1,469,442)
Net Sell
11 txns
Insider
Lewis William
Role
Chair and CEO
Sold
10,699 shs ($1.47M)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Exercise | Stock Option (right to buy) | 6,259 | $0.00 | -- |
| Exercise | Stock Option (right to buy) | 4,440 | $0.00 | -- |
| Exercise | Common Stock | 6,259 | $30.46 | $191K |
| Exercise | Common Stock | 4,440 | $17.16 | $76K |
| Sale | Common Stock | 433 | $134.18 | $58K |
| Sale | Common Stock | 599 | $135.18 | $81K |
| Sale | Common Stock | 5,318 | $137.01 | $729K |
| Sale | Common Stock | 2,721 | $137.86 | $375K |
| Sale | Common Stock | 1,247 | $139.09 | $173K |
| Sale | Common Stock | 381 | $139.60 | $53K |
| holding | Common Stock | -- | -- | -- |
Holdings After Transaction:
Stock Option (right to buy) — 31,296 shares (Direct, null);
Common Stock — 307,444 shares (Direct, null);
Common Stock — 233,924 shares (Indirect, By trust)
Footnotes (1)
- This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025 in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. This is the weighted average sales price representing 433 shares sold at prices ranging from $133.88 to $134.69 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 599 shares sold at prices ranging from $135.06 to $135.50 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 5,318 shares sold at prices ranging from $136.32 to $137.30 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 2,721 shares sold at prices ranging from $137.32 to $138.28 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 1,247 shares sold at prices ranging from $138.52 to $139.43 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. The options became exercisable based on the following vesting schedule: 25% vested on the first anniversary of the grant date and an additional 12.5% vested on each sixth month anniversary date thereafter through the fourth anniversary of the date of grant.
Key Figures
Shares sold: 10,699 shares
Shares acquired via options: 10,699 shares
Sale price (highest block): $139.60 per share
+4 more
7 metrics
Shares sold
10,699 shares
Total open-market sales on May 4, 2026
Shares acquired via options
10,699 shares
Total from option exercises on May 4, 2026
Sale price (highest block)
$139.60 per share
381 shares of common stock sold
Sale price (other blocks)
$139.09–$134.18 per share
Weighted averages for multiple sale tranches
Option exercise price 1
$17.16 per share
4,440 stock options exercised into common shares
Option exercise price 2
$30.46 per share
6,259 stock options exercised into common shares
Indirect trust holdings
233,924 shares
Common stock held indirectly by trust
Key Terms
Rule 10b5-1 trading plan, weighted average sales price, Stock Option (right to buy), derivative security, +1 more
5 terms
Rule 10b5-1 trading plan financial
"This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025"
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
weighted average sales price financial
"This is the weighted average sales price representing 433 shares sold at prices ranging from $133.88 to $134.69 per share"
Stock Option (right to buy) financial
"security_title: "Stock Option (right to buy)" with underlying security title Common Stock"
derivative security financial
"transaction_code_description: "Exercise or conversion of derivative security""
A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.
indirect ownership financial
"direct_or_indirect: "I" and nature_of_ownership: "By trust""
FAQ
What insider transactions did Insmed (INSM) CEO William Lewis report?
William Lewis reported selling 10,699 shares of Insmed common stock and exercising stock options for 10,699 shares. The sales occurred in multiple open-market trades, while the exercises converted options into shares at lower strike prices of $17.16 and $30.46.
Were Insmed (INSM) CEO William Lewis’s stock sales pre-planned?
Yes. A footnote states the transactions were effected under a Rule 10b5-1 trading plan adopted on September 4, 2025. Such plans pre-schedule trades, indicating these sales followed an established plan rather than ad hoc market timing decisions.
How many stock options did the Insmed (INSM) CEO exercise in this Form 4?
Lewis exercised options for a total of 10,699 shares of Insmed common stock. This included 4,440 options with a $17.16 exercise price and 6,259 options with a $30.46 exercise price, turning previously granted derivatives into directly held shares.
What does the weighted average sales price mean in the Insmed (INSM) Form 4?
Weighted average sales prices summarize multiple trades within a disclosed range into a single average figure. For example, 5,318 shares were sold at a weighted average of $137.01 within a $136.32–$137.30 range, with exact per-trade details available on request to the reporting person.