Were the Insmed (INSM) CMO’s share sales made under a Rule 10b5-1 plan?

Yes. The filing states the transactions were effected under a Rule 10b5-1 trading plan adopted on February 27, 2025, indicating the timing of sales was pre-arranged rather than decided at the time of trading.

Insmed (INSM) CMO sells 12,949 shares under Rule 10b5-1 plan

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

Insmed Inc.'s Chief Medical Officer, Martina Flammer, M.D., reported an exercise-and-sell transaction in company stock. She exercised stock options to acquire 12,949 shares of common stock at $17.07 per share, then sold 12,949 shares in open-market transactions at weighted average prices of $100.35 for 12,119 shares and $101.18 for 830 shares. The sales were made pursuant to a Rule 10b5-1 trading plan adopted on February 27, 2025. Following these transactions, she holds 83,243 shares of Insmed common stock directly.

Insider Trade Summary 10b5-1

Net Seller: 12,949 shares ($1,300,121)

Net Sell 4 txns

Insider Flammer Martina M.D.

Role Chief Medical Officer

Sold 12,949 shs ($1.30M)

Type	Security	Shares	Price	Value
Exercise	Stock Option (right to buy)	12,949	$0.00	--
Exercise	Common Stock	12,949	$17.07	$221K
Sale	Common Stock	12,119	$100.35	$1.22M
Sale	Common Stock	830	$101.18	$84K

Holdings After Transaction: Stock Option (right to buy) — 0 shares (Direct, null); Common Stock — 96,192 shares (Direct, null)

Footnotes (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. This is the weighted average sales price representing 12,119 shares sold at prices ranging from $100.00 to $100.96 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 830 shares sold at prices ranging from $101.11 to $101.36 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.

Key Figures

Shares sold: 12,949 shares Weighted avg sale price (12,119 shares): $100.35 per share Weighted avg sale price (830 shares): $101.18 per share +2 more

5 metrics

Shares sold 12,949 shares Open-market sales of common stock on May 11, 2026

Weighted avg sale price (12,119 shares) $100.35 per share Common stock sales with prices from $100.00 to $100.96

Weighted avg sale price (830 shares) $101.18 per share Common stock sales with prices from $101.11 to $101.36

Options exercised 12,949 shares at $17.07 Stock option exercise converting into common stock

Shares held after transactions 83,243 shares Direct common stock ownership following May 11, 2026 trades

Key Terms

Rule 10b5-1 trading plan, weighted average sales price, Stock Option (right to buy), vested

4 terms

Rule 10b5-1 trading plan regulatory

"This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on February 27, 2025"

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 12,119 shares sold at prices ranging from $100.00 to $100.96 per share"

Stock Option (right to buy) financial

"security_title: "Stock Option (right to buy)""

vested financial

"25% vested on the first anniversary of the grant date and an additional 12.5% vested on each sixth month anniversary date thereafter"

Form 4 Insider Transactions: What Each Field Means →

05/13/2026 - 04:50 PM

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).

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^*

Flammer Martina M.D.

(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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/11/2026

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

X	Form 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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/11/2026		M⁽¹⁾		12,949	A	$17.07	96,192	D
Common Stock	05/11/2026		S⁽¹⁾		12,119	D	$100.35⁽²⁾	84,073	D
Common Stock	05/11/2026		S⁽¹⁾		830	D	$101.18⁽³⁾	83,243	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option (right to buy)	$17.07	05/11/2026		M⁽¹⁾			12,949	⁽⁴⁾	05/11/2032	Common Stock	12,949	$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 12,119 shares sold at prices ranging from $100.00 to $100.96 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 830 shares sold at prices ranging from $101.11 to $101.36 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. 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/ Martina Flammer, M.D., by Michael A. Smith as Attorney-in-fact	05/13/2026
	** 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).
** 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)

Source: View Original Filing on SEC EDGAR

FAQ

What did Insmed (INSM) Chief Medical Officer Martina Flammer report in this Form 4?

Martina Flammer reported exercising options for 12,949 Insmed shares at $17.07 and selling 12,949 shares in open-market trades at weighted average prices around $100–$101, all under a pre-arranged Rule 10b5-1 trading plan.

How many Insmed (INSM) shares did the CMO sell and at what prices?

She sold 12,949 Insmed common shares, including 12,119 shares at a weighted average price of $100.35 and 830 shares at a weighted average price of $101.18, with actual prices ranging from $100.00 to $101.36 per share.

What stock options did Martina Flammer exercise in this Insmed (INSM) filing?

She exercised stock options for 12,949 Insmed common shares at an exercise price of $17.07 per share. The options vested over four years, with 25% on the first anniversary and 12.5% every six months thereafter.

How many Insmed (INSM) shares does the CMO hold after these transactions?

After exercising options and selling shares, Martina Flammer holds 83,243 Insmed common shares directly. This reflects her remaining equity position disclosed in the filing following the reported transactions on May 11, 2026.