[Form 4] INSMED Inc Insider Trading Activity

Rhea-AI Filing Summary

Insmed (INSM) reported an insider transaction by its Chief Legal Officer. On 11/03/2025, the officer exercised 27,130 stock options at an exercise price of $23.75 and sold shares in multiple tranches under a Rule 10b5-1 trading plan adopted on February 27, 2025.

The sales were executed at weighted average prices ranging from $181.01 to $187.97, with the filing noting price ranges and an undertaking to provide per-price breakdowns upon request. Following the reported transactions, the officer beneficially owned 54,902 shares directly.

Insights

Insider transactions analyst

Planned option exercise and sales; administrative in nature.

The reporting officer exercised 27,130 options at an exercise price of $23.75 and sold shares in multiple tranches on 11/03/2025. The filing states the activity was conducted under a Rule 10b5-1 trading plan adopted on February 27, 2025, which pre-schedules trades.

Weighted average sale prices ranged from $181.01 to $187.97, with detailed ranges provided for each tranche. After the transactions, direct beneficial ownership stood at 54,902 shares. This is a routine insider Form 4 disclosure and, by itself, does not change the company’s fundamentals.

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
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^*

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)
11/03/2025

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	11/03/2025		M(1)		27,130	A	$23.75	82,032	D
Common Stock	11/03/2025		S(1)		1,342	D	$181.01(2)	80,690	D
Common Stock	11/03/2025		S(1)		7,619	D	$181.88(3)	73,071	D
Common Stock	11/03/2025		S(1)		4,286	D	$182.6(4)	68,785	D
Common Stock	11/03/2025		S(1)		4,032	D	$183.92(5)	64,753	D
Common Stock	11/03/2025		S(1)		3,243	D	$184.91(6)	61,510	D
Common Stock	11/03/2025		S(1)		3,636	D	$185.93(7)	57,874	D
Common Stock	11/03/2025		S(1)		1,572	D	$187.15(8)	56,302	D
Common Stock	11/03/2025		S(1)		1,400	D	$187.97(9)	54,902	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)	$23.75	11/03/2025		M(1)			27,130	(10)	01/03/2030	Common Stock	27,130	$0	0	D

Explanation of Responses:

1. This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on February 27, 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 1,342 shares sold at prices ranging from $180.29 to $181.19 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 7,619 shares sold at prices ranging from $181.30 to $182.29 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 4,286 shares sold at prices ranging from $182.30 to $183.03 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 4,032 shares sold at prices ranging from $183.49 to $184.48 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 3,243 shares sold at prices ranging from $184.50 to $185.48 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. This is the weighted average sales price representing 3,636 shares sold at prices ranging from $185.51 to $186.45 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.

8. This is the weighted average sales price representing 1,572 shares sold at prices ranging from $186.61 to $187.53 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.

9. This is the weighted average sales price representing 1,400 shares sold at prices ranging from $187.88 to $188.13 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.

10. 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. All options are currently exercisable.

Remarks:

	/s/ Michael A. Smith	11/05/2025
	** 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).
** 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.

FAQ

What did INSM's insider report on Form 4?

The Chief Legal Officer exercised 27,130 stock options at $23.75 and sold shares in multiple tranches on 11/03/2025.

At what prices were INSM shares sold by the officer?

Weighted average sale prices ranged from $181.01 to $187.97, with specified price ranges for each tranche.

How many INSM shares does the officer own after the transactions?

Following the reported transactions, the officer directly beneficially owned 54,902 shares.

What was the exercise price of the options exercised?

The stock options were exercised at an exercise price of $23.75 per share.

When was the 10b5-1 trading plan adopted?

The plan was adopted on February 27, 2025.

What is the officer’s role at Insmed (INSM)?

The reporting person is an Officer, serving as Chief Legal Officer.

What was the transaction date reported?

The earliest transaction date reported was 11/03/2025.