STOCK TITAN

INSMED (INSM) CEO Lewis exercises options and sells 21,398 shares under 10b5-1 plan

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

INSMED Inc Chair and CEO William Lewis reported option exercises and share sales in INSMED common stock. On June 25, 2026, he exercised stock options covering 21,398 shares at strike prices of $17.16 and $30.46 per share, converting derivative awards into common stock.

On the same date, he sold 21,398 shares in multiple open-market transactions at weighted average prices ranging from about $101.78 to $106.45 per share, pursuant to a pre-arranged Rule 10b5-1 trading plan adopted on September 4, 2025. After these transactions, Lewis holds 271,435 shares directly and 233,924 shares indirectly through a trust.

Positive

  • None.

Negative

  • None.
Insider Lewis William
Role Chair and CEO
Sold 21,398 shs ($2.21M)
Type Security Shares Price Value
Exercise Stock Option (right to buy) 12,518 $0.00 --
Exercise Stock Option (right to buy) 8,880 $0.00 --
Exercise Common Stock 12,518 $30.46 $381K
Exercise Common Stock 8,880 $17.16 $152K
Sale Common Stock 12,091 $102.34 $1.24M
Sale Common Stock 1,836 $103.10 $189K
Sale Common Stock 3,723 $104.28 $388K
Sale Common Stock 2,456 $105.27 $259K
Sale Common Stock 1,292 $106.27 $137K
holding Common Stock -- -- --
Holdings After Transaction: Stock Option (right to buy) — 12,519 shares (Direct, null); Common Stock — 271,435 shares (Direct, null); Common Stock — 233,924 shares (Indirect, By trust)
Footnotes (1)
  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 12,091 shares sold at prices ranging from $101.78 to $102.77 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 1,836 shares sold at prices ranging from $102.78 to $103.58 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 3,723 shares sold at prices ranging from $103.87 to $104.75 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 2,456 shares sold at prices ranging from $104.90 to $105.88 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 1,292 shares sold at prices ranging from $105.90 to $106.45 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.
Shares sold 21,398 shares Net open-market sales on June 25, 2026
Sale prices range $101.78–$106.45 per share Weighted average price ranges from footnotes
Options exercised 21,398 shares Stock option exercises on June 25, 2026
Option strike prices $17.16 and $30.46 per share Conversion prices for exercised stock options
Direct holdings after 271,435 shares Common stock held directly after transactions
Indirect holdings after 233,924 shares Common stock held indirectly by trust
10b5-1 plan adoption date September 4, 2025 Date CEO adopted trading plan for these sales
Option expiration dates May 17, 2027 and January 4, 2028 Expiration for original stock option grants
Rule 10b5-1 trading plan regulatory
"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 12,091 shares sold"
Stock Option (right to buy) financial
"security_title": "Stock Option (right to buy)""
derivative security financial
"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.
vesting schedule financial
"The options became exercisable based on the following vesting schedule"
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.
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Learn about SEC filing dates
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a 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). See Instruction 10.
1. Name and Address of Reporting Person*
Lewis William

(Last)(First)(Middle)
700 US HIGHWAY 202/206

(Street)
BRIDGEWATER NEW JERSEY 08807

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
INSMED Inc [ INSM ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
XOfficer (give title below)Other (specify below)
Chair and CEO
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/25/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock06/25/2026M(1)12,518A$30.46271,435D
Common Stock06/25/2026M(1)8,880A$17.16280,315D
Common Stock06/25/2026S(1)12,091D$102.34(2)268,224D
Common Stock06/25/2026S(1)1,836D$103.1(3)266,388D
Common Stock06/25/2026S(1)3,723D$104.28(4)262,665D
Common Stock06/25/2026S(1)2,456D$105.27(5)260,209D
Common Stock06/25/2026S(1)1,292D$106.27(6)258,917D
Common Stock233,924IBy trust
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (right to buy)$30.4606/25/2026M(1)12,518 (7)01/04/2028Common Stock12,518$012,519D
Stock Option (right to buy)$17.1606/25/2026M(1)8,880 (7)05/17/2027Common Stock8,880$08,880D
Explanation of Responses:
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.
2. This is the weighted average sales price representing 12,091 shares sold at prices ranging from $101.78 to $102.77 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.
3. This is the weighted average sales price representing 1,836 shares sold at prices ranging from $102.78 to $103.58 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.
4. This is the weighted average sales price representing 3,723 shares sold at prices ranging from $103.87 to $104.75 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.
5. This is the weighted average sales price representing 2,456 shares sold at prices ranging from $104.90 to $105.88 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.
6. This is the weighted average sales price representing 1,292 shares sold at prices ranging from $105.90 to $106.45 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.
7. 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.
Remarks:
/s/ William Lewis, by Michael A. Smith as Attorney-in-fact06/26/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What did INSMED (INSM) CEO William Lewis report in this Form 4?

Lewis reported exercising stock options and selling common shares of INSMED. He exercised options for 21,398 shares and sold 21,398 shares in open-market transactions, converting option awards into cash while maintaining a substantial remaining equity stake.

How many INSMED (INSM) shares did William Lewis sell and at what prices?

Lewis sold 21,398 INSMED common shares in several open-market trades. Weighted average sale prices ranged from about $101.78 to $106.45 per share, with each trade’s price range detailed via weighted-average footnotes available to regulators and shareholders on request.

What stock options did INSMED (INSM) CEO William Lewis exercise?

He exercised stock options covering 21,398 shares of INSMED common stock. The options had exercise prices of $17.16 and $30.46 per share, reflecting previously granted equity awards that vested over time according to a defined vesting schedule described in the filing footnotes.

How many INSMED (INSM) shares does William Lewis hold after these transactions?

Following the reported transactions, Lewis holds 271,435 INSMED shares directly. In addition, he has 233,924 shares held indirectly through a trust, giving him a sizeable ongoing ownership position in the company after exercising options and selling an equivalent number of shares.

Were the INSMED (INSM) CEO’s stock sales made under a 10b5-1 plan?

Yes. The filing states the sales were executed under a Rule 10b5-1 trading plan. This plan was adopted on September 4, 2025, and allows pre-scheduled trades, indicating the timing of these sales was determined in advance rather than decided opportunistically.