Insmed (INSM) CEO sells shares, 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 mix of stock sales and option exercises in company common stock. On May 18, 2026, he sold a total of 25,564 shares in three open-market transactions at weighted average prices in the $105–$107 per share range, executed under a preset Rule 10b5-1 trading plan adopted on September 4, 2025.
On the same date, Lewis also exercised 10,699 stock options to acquire common shares, with exercise prices of $17.16 and $30.46 per share. The filing shows both direct holdings and additional shares held indirectly through a trust, indicating he retains a substantial ownership interest after these transactions.
Positive
- None.
Negative
- None.
Insider Trade Summary 10b5-1
Net Seller: 25,564 shares ($2,718,224)
Net Sell
8 txns
Insider
Lewis William
Role
Chair and CEO
Sold
25,564 shs ($2.72M)
| 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 | 5,753 | $105.32 | $606K |
| Sale | Common Stock | 11,836 | $106.39 | $1.26M |
| Sale | Common Stock | 7,975 | $106.97 | $853K |
| holding | Common Stock | -- | -- | -- |
Holdings After Transaction:
Stock Option (right to buy) — 25,037 shares (Direct, null);
Common Stock — 294,161 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 5,753 shares sold at prices ranging from $104.73 to $105.71 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 11,836 shares sold at prices ranging from $105.73 to $106.72 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 7,975 shares sold at prices ranging from $106.73 to $107.36 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: 25,564 shares
First sale price: $106.97 per share
Second sale price: $106.39 per share
+5 more
8 metrics
Shares sold
25,564 shares
Total open-market sales on May 18, 2026
First sale price
$106.97 per share
Weighted average price for 7,975 shares sold
Second sale price
$106.39 per share
Weighted average price for 11,836 shares sold
Third sale price
$105.32 per share
Weighted average price for 5,753 shares sold
Options exercised
10,699 shares
Total common shares from option exercises on May 18, 2026
Option strike price 1
$17.16 per share
Exercise price for 4,440 stock options
Option strike price 2
$30.46 per share
Exercise price for 6,259 stock options
Indirect trust holding
233,924 shares
Common stock held indirectly by trust as of May 18, 2026
Key Terms
Rule 10b5-1 trading plan, weighted average sales price, Stock Option (right to buy), Common Stock, +1 more
5 terms
Rule 10b5-1 trading plan regulatory
"This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person..."
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 5,753 shares sold at prices ranging..."
Stock Option (right to buy) financial
"Stock Option (right to buy) ... underlying security title Common Stock..."
Common Stock financial
"security_title: Common Stock ... transaction_type: non-derivative"
Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.
vesting schedule financial
"The options became exercisable based on the following vesting schedule: 25% vested on the first anniversary..."
A vesting schedule is a timeline that determines when someone gains full ownership of certain benefits, such as company stock or retirement contributions. Think of it like earning the right to own a gift gradually over time, rather than receiving it all at once. It matters to investors because it affects when they can fully access or sell these benefits, influencing their financial planning and decision-making.
FAQ
What insider transactions did INSMED (INSM) CEO William Lewis report?
William Lewis reported open-market sales and option exercises in Insmed common stock. He sold 25,564 shares and exercised 10,699 stock options, reflecting a mix of liquidity-taking and continued equity exposure through direct and indirect holdings.
What stock options did the INSMED (INSM) CEO exercise in this Form 4?
He exercised 10,699 stock options for Insmed common stock. The options had exercise prices of $17.16 and $30.46 per share, reflecting previously granted equity awards that had vested according to a stated multi-year vesting schedule described in the filing footnotes.
What does the vesting schedule note in the INSMED (INSM) Form 4 mean?
The vesting note explains that 25% of the options became exercisable on the first anniversary of the grant, with 12.5% vesting every six months thereafter through the fourth anniversary. This describes a typical multi-year incentive structure for executive compensation in stock options.