Insmed (INSM) CLO exercises options and sells 24,774 shares

Rhea-AI Filing Summary

Insmed Inc’s Chief Legal Officer, Michael Alexander Smith, reported option exercises and share sales in company stock. On February 24, 2026, he exercised a stock option for 20,248 shares, converting a derivative security into common stock at a reported price of $17.07 per share.

On the same date, he sold a total of 24,774 shares of common stock in open-market transactions at weighted average prices of $153.93, $155.06, and $156.53 per share, under a Rule 10b5-1 trading plan adopted on November 7, 2025. After these transactions, he directly owned 51,871 common shares of Insmed.

SEC Form 4

FORM 4

UNITED 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
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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^*

Smith Michael Alexander

(Last) (First) (Middle)

700 US HIGHWAY 202/206

(Street)

BRIDGEWATER NJ 08807

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
INSMED Inc [ INSM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/24/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/24/2026		M(1)		20,248	A	$17.07	76,645	D
Common Stock	02/24/2026		S(1)		4,852	D	$153.93(2)	71,793	D
Common Stock	02/24/2026		S(1)		4,151	D	$155.06(3)	67,642	D
Common Stock	02/24/2026		S(1)		15,771	D	$156.53(4)	51,871	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	$17.07	02/24/2026		M(1)			20,248	(5)	05/11/2032	Common Stock	20,248	$0	14,282	D

Explanation of Responses:

1. This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on November 7, 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 4,852 shares sold at prices ranging from $153.47 to $154.46 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 4,151 shares sold at prices ranging from $154.47 to $155.45 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.

4. This is the weighted average sales price representing 15,771 shares sold at prices ranging from $156.00 to $156.86 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. The options become exercisable based on the following vesting schedule: 25% vest on the first anniversary of the grant date and an additional 12.5% vest on each sixth month anniversary date thereafter through the fourth anniversary of the date of grant.

Remarks:

	/s/ Michael A. Smith	02/26/2026
	** Signature of Reporting Person	Date
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).
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FAQ

What insider transactions did INSM Chief Legal Officer Michael Alexander Smith report?

Michael Alexander Smith reported exercising options for 20,248 Insmed shares and selling 24,774 common shares. All transactions occurred on February 24, 2026, and were executed in open-market trades under a pre-arranged Rule 10b5-1 trading plan adopted in November 2025.

How many INSM shares did the insider sell and at what prices?

The insider sold 24,774 Insmed common shares in three blocks. Weighted average sale prices were $153.93, $155.06, and $156.53 per share, with each block covering thousands of shares sold within narrow intraday price ranges disclosed in the filing’s footnotes.

Were the INSM insider sales made under a Rule 10b5-1 trading plan?

Yes. The filing states the transactions were executed under a Rule 10b5-1 trading plan adopted on November 7, 2025. Such plans allow insiders to schedule trades in advance, providing a structured framework for selling shares over time.

How many INSM shares does the Chief Legal Officer own after these transactions?

Following the reported option exercise and subsequent sales, Michael Alexander Smith directly owns 51,871 Insmed common shares. This post-transaction holding figure reflects all trades reported for February 24, 2026, and represents his remaining direct equity stake.

What type of derivative security did the INSM insider exercise?

He exercised a stock option, described as a “Stock Option (right to buy)” in the filing. The option exercise converted 20,248 option rights into Insmed common shares, using a reported exercise price of $17.07 per share as part of the transaction details.

What is the vesting schedule for the INSM stock options mentioned?

The options vest 25% on the first anniversary of the grant date, then 12.5% every six months through the fourth anniversary. This staggered vesting schedule gradually increases exercisable options over four years, aligning longer-term incentives with the company’s equity program.