William Lewis - 19 Feb 2026 Form 4 Insider Report for INSMED Inc (INSM)

Role
Chair and CEO, Director
Signature
/s/ William Lewis, by Michael A. Smith as Attorney-in-fact
Issuer symbol
INSM
Transactions as of
19 Feb 2026
Net transactions value
-$1,348,417
Form type
4
Filing time
23 Feb 2026, 16:34:10 UTC
Previous filing
11 Feb 2026
Next filing
05 Mar 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Lewis William Chair and CEO, Director 700 US HIGHWAY 202/206, BRIDGEWATER /s/ William Lewis, by Michael A. Smith as Attorney-in-fact 23 Feb 2026 0001402051

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction INSM Common Stock Options Exercise $190,649 +6,259 +2.1% $30.46 307,444 19 Feb 2026 Direct F1
transaction INSM Common Stock Options Exercise $76,190 +4,440 +1.4% $17.16 311,884 19 Feb 2026 Direct F1
transaction INSM Common Stock Sale $296,550 -1,988 -0.64% $149.17 309,896 19 Feb 2026 Direct F1, F2
transaction INSM Common Stock Sale $283,839 -1,891 -0.61% $150.10 308,005 19 Feb 2026 Direct F1, F3
transaction INSM Common Stock Sale $515,773 -3,413 -1.1% $151.12 304,592 19 Feb 2026 Direct F1, F4
transaction INSM Common Stock Sale $361,114 -2,377 -0.78% $151.92 302,215 19 Feb 2026 Direct F1, F5
transaction INSM Common Stock Sale $157,981 -1,030 -0.34% $153.38 301,185 19 Feb 2026 Direct F1, F6
holding INSM Common Stock 233,924 19 Feb 2026 By the Katie Procter Dynasty Trust
holding INSM Common Stock 50,500 19 Feb 2026 By the William Lewis Family Legacy Trust

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction INSM Stock Option (right to buy) Options Exercise $0 -6,259 -9.1% $0.000000 62,591 19 Feb 2026 Common Stock 6,259 $30.46 Direct F1, F7
transaction INSM Stock Option (right to buy) Options Exercise $0 -4,440 -9.1% $0.000000 44,400 19 Feb 2026 Common Stock 4,440 $17.16 Direct F1, F7
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 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.
F2 This is the weighted average sales price representing 1,988 shares sold at prices ranging from $148.51 to $149.50 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.
F3 This is the weighted average sales price representing 1,891 shares sold at prices ranging from $149.53 to $150.50 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.
F4 This is the weighted average sales price representing 3,413 shares sold at prices ranging from $150.54 to $151.51 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.
F5 This is the weighted average sales price representing 2,377 shares sold at prices ranging from $151.56 to $152.43 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.
F6 This is the weighted average sales price representing 1,030 shares sold at prices ranging from $153.00 to $153.78 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.
F7 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.