[Form 4] INSMED Inc Insider Trading Activity

Rhea-AI Filing Summary

INSMED Inc (INSM) reporting person S. Nicole Schaeffer, Chief People Strategy Officer, completed multiple transactions on 09/12/2025 under a 10b5-1 plan. She exercised 56,520 stock options with a $23.75 exercise price, resulting in ownership of 56,520 shares from the exercise and a reported pre-sale beneficial ownership of 112,981 shares. On the same date she sold a total of 76,520 shares in four separate sell transactions at weighted average prices of $144.6, $145.67, $146.57, and $147.46, leaving her with 36,461 shares beneficially owned following the reported transactions. The sales were effected pursuant to a 10b5-1 trading plan adopted June 13, 2025, and the filing is signed by an attorney-in-fact on behalf of the reporting person.

Positive

• Option exercise at $23.75 yielded a substantial gain opportunity given subsequent sale prices above $144 per share.
• Transactions effected under a 10b5-1 trading plan, indicating pre-established, rule-compliant disposition of shares.

Negative

• Large net reduction in beneficial ownership: beneficial shares fell to 36,461 after selling 76,520 shares.
• Significant volume sold on single date (76,520 shares) could be perceived negatively by some investors monitoring insider holdings.

Insights

Securities Analyst

TL;DR: Officer exercised options at $23.75 then sold most shares under a 10b5-1 plan, reducing beneficial ownership materially.

The filing shows an in-the-money option exercise converting 56,520 options into shares at a low exercise price of $23.75, followed by contemporaneous market sales of 76,520 shares at weighted average prices between $144.06 and $148.00 per share under a 10b5-1 plan adopted June 13, 2025. The net effect is a reduction in reported beneficial ownership to 36,461 shares. These are routine, pre-planned transactions rather than ad hoc dispositions; materiality lies in the size of the sales relative to the reporting person's prior ownership.

Corporate Governance Expert

TL;DR: Transactions appear compliant with Rule 10b5-1; documentation notes weighted-average pricing disclosures and attorney-in-fact signature.

The Form 4 discloses adoption of a 10b5-1 plan (June 13, 2025) and provides weighted-average sale price ranges with commitments to provide per-price breakdowns on request, which aligns with disclosure norms. The filing is executed by an attorney-in-fact, and option vesting details are provided. No indications of insider timing or amendments are present in the filing; the pattern is consistent with pre-arranged liquidity planning by an executive.

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).

1. Name and Address of Reporting Person^*

Schaeffer Orlov S Nicole

(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 People Strategy Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/12/2025

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	09/12/2025		M(1)		56,520	A	$23.75	112,981	D
Common Stock	09/12/2025		S(1)		32,091	D	$144.6(2)	80,890	D
Common Stock	09/12/2025		S(1)		30,967	D	$145.67(3)	49,923	D
Common Stock	09/12/2025		S(1)		7,304	D	$146.57(4)	42,619	D
Common Stock	09/12/2025		S(1)		6,158	D	$147.46(5)	36,461	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	09/12/2025		M(1)			56,520	(6)	01/03/2030	Common Stock	56,520	$0	0	D

Explanation of Responses:

1. This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on June 13, 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 32,091 shares sold at prices ranging from $144.06 to $145.05 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 30,967 shares sold at prices ranging from $145.06 to $146.02 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 7,304 shares sold at prices ranging from $146.08 to $147.06 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 6,158 shares sold at prices ranging from $147.12 to $148.00 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. 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/ S. Nicole Schaeffer, by Michael A. Smith as Attorney-in-fact	09/15/2025
	** 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 transactions did INSM insider S. Nicole Schaeffer report on Form 4?

The filing reports exercise of 56,520 stock options at $23.75 and sales of a total of 76,520 shares on 09/12/2025 under a 10b5-1 plan.

How many shares does the reporting person own after the transactions?

The reporting person beneficially owned 36,461 shares following the reported transactions.

At what prices were the shares sold?

Sales were reported as weighted-average prices across four ranges: $144.06–$145.05, $145.06–$146.02, $146.08–$147.06, and $147.12–$148.00.

Were these sales part of a prearranged trading plan?

Yes; the transactions were effected pursuant to a 10b5-1 trading plan adopted June 13, 2025.

When did the reporting person adopt the 10b5-1 plan?

The Form 4 states the 10b5-1 trading plan was adopted on June 13, 2025.