INSM insider files Rule 144 sales of common stock

INSM reported officer stock sale transactions under Rule 144.

Rhea-AI Filing Summary

INSM reported officer stock sale transactions under Rule 144. The filing lists recent dispositions of Common Stock executed through Merrill Lynch on 06/01/2026 and shows multiple seller entries for Martina Flammer. Examples include sales on 06/03/2026 (2,566 shares), 05/14/2026 (10,479 shares) and 05/13/2026 (7,854 shares). The submission uses a broker-dealer address in Washington, D.C., and is recorded on 06/05/2026.

Insights

Corporate Governance/Insider Transactions Analyst

Rule 144 dispositions by an insider are disclosed; this shows routine selling activity.

The filing lists multiple reported dispositions of Common Stock by Martina Flammer with specific trade dates and share counts visible in the excerpt. The transactions are recorded as brokered through Merrill Lynch and the record shows a filing date of 06/05/2026.

These entries are routine compliance disclosures of insider sales under Rule 144. Cash-flow treatment and any trading-plan attribution are not shown in the provided excerpt; subsequent filings or footnotes would be required for those details.

Key Figures

Sale - 06/03/2026: 2,566 shares Sale - 05/14/2026: 10,479 shares Sale - 05/13/2026: 7,854 shares +2 more

5 metrics

Sale - 06/03/2026 2,566 shares disposition by Martina Flammer

Sale - 05/14/2026 10,479 shares disposition by Martina Flammer

Sale - 05/13/2026 7,854 shares disposition by Martina Flammer

Form record date 06/05/2026 Form 144 filing/record date

Broker-dealer Merrill Lynch (address listed) execution agent shown on the form

Key Terms

Rule 144, Form 144, Stock Plan Activity

3 terms

Rule 144 regulatory

"144: Securities Sold During The Past 3 Months"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Form 144 regulatory

"CONTENT TO ANALYZE: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Stock Plan Activity financial

"Common | 06/01/2026 | Stock Plan Activity"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions does INSM disclose in this Form 144?

The filing discloses Rule 144 dispositions of Common Stock by Martina Flammer. Examples include sales of 2,566, 10,479, and 7,854 shares on the listed dates.

Who executed the trades reported in INSM's Form 144?

Trades are shown as executed through Merrill Lynch (address listed). The broker-dealer entry on the cover indicates Merrill Lynch handled the reported transactions.

What are the filing and effective dates shown in the excerpt for INSM?

The excerpt shows an entry date of 06/01/2026 for stock plan activity and a filing/record date of 06/05/2026 on the Form 144 cover information.

Does the excerpt state who received proceeds from these sales?

The provided excerpt does not state the cash-flow recipient or use of proceeds; it lists the dispositions, broker, dates, and share counts without proceeds details.

Are the post-transaction holdings shown for Martina Flammer in the excerpt?

The excerpt includes numbers adjacent to each sale row that appear to be holdings (e.g., 262,424, 1,231,599, 897,137), but the filing text does not label them explicitly in the provided snippet.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 06/05/2026 - 04:18 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001796960
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	INSMED INC
SEC File Number	000-30739
Address of Issuer	700 US Highway 202/206 Bridgewater NEW JERSEY 08807
Phone	9089779900
Name of Person for Whose Account the Securities are To Be Sold	Martina Flammer
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Merrill Lynch 1800 K ST NW Suite 800 Washington DC 20006	1858	192811	216752451	06/05/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	06/01/2026	Stock Plan Activity	Issuer			1858	06/01/2026	n/a

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Martina Flammer 700 US Highway 202/206 Bridgewater NJ 08807	Common	06/03/2026	2566	262424
Martina Flammer 700 US Highway 202/206 Bridgewater NJ 08807	Common	05/14/2026	10479	1231599
Martina Flammer 700 US Highway 202/206 Bridgewater NJ 08807	Common	05/13/2026	7854	897137
Martina Flammer 700 US Highway 202/206 Bridgewater NJ 08807	Common	05/11/2026	12949	1300105

144: Remarks and Signature

Remarks
Date of Notice	06/05/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	02/27/2025
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	Martina Flammer
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)