INSM files Form 144 for proposed common stock sales

INSM reported proposed sales of Common Stock under a Form 144 notice.

Rhea-AI Filing Summary

INSM reported proposed sales of Common Stock under a Form 144 notice. The filing lists securities to be sold tied to stock plan activity dated 06/01/2026 and a separate reported sale of 8,272 shares on 05/13/2026 by Sara Bonstein.

Insights

Securities Compliance Counsel

Procedural notice of proposed resale under Rule 144; routine compliance filing.

The entry reports proposed sales of Common Stock connected to stock plan activity dated 06/01/2026 and a recent sale of 8,272 shares on 05/13/2026. This is a regulatory disclosure of intended or recent transactions.

Timing, proceeds treatment, and whether transactions complete are not detailed; subsequent filings or trade reporting will show execution and cash‑flow outcomes.

Equity Capital Markets Analyst

Notice describes issuer stock plan movement and an individual sale; no material corporate change.

The excerpt lists a stock plan activity entry (06/01/2026) and a named seller, Sara Bonstein, with a sale of 8,272 shares on 05/13/2026. There is no offering size or proceeds detail shown.

Market impact depends on whether the proposed sales are executed; the filing itself is administrative.

Key Figures

Market: NASDAQ Sale reported (past 3 months): 8,272 shares Stock plan activity date: 06/01/2026 +2 more

5 metrics

Market NASDAQ Listed market for the securities in the filing

Sale reported (past 3 months) 8,272 shares Sale date <date>05/13/2026</date> by Sara Bonstein

Stock plan activity date 06/01/2026 Date tied to securities to be sold entry labeled 'Stock plan activity'

Filer/issuer reference date 06/03/2026 Filer information line shows this date

Item numeric entries 2404; 245857; 216752451 Numeric lines present in the securities information block

Key Terms

Form 144, stock plan activity, Securities Sold During The Past 3 Months

3 terms

Form 144 regulatory

"144: Securities To Be Sold"

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"

Securities Sold During The Past 3 Months regulatory

"144: Securities Sold During The Past 3 Months"

FAQ

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

What does INSM's Form 144 filing report?

It reports proposed sales of Common Stock under Rule 144. The filing references stock plan activity dated 06/01/2026 and a reported sale of 8,272 shares on 05/13/2026 by Sara Bonstein, listing NASDAQ as the market.

Who is the seller named in the INSM excerpt?

The filing names Sara Bonstein at a Bridgewater, NJ address as a seller. It shows she sold 8,272 shares on 05/13/2026, recorded in the "Securities Sold During The Past 3 Months" section of the notice.

Does the filing state how many shares are being registered or proceeds amount?

No specific aggregate offering or proceeds amount is provided in the excerpt. The text lists entries and dates including a stock plan activity on 06/01/2026, but it does not disclose an aggregate registered amount or monetary proceeds.

Which market and dates are shown in the INSM excerpt?

The excerpt identifies NASDAQ as the market and includes dates: 05/13/2026 for the recorded sale of 8,272 shares, 06/01/2026 for stock plan activity, and a filer/issuer reference dated 06/03/2026.

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

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Accepted by SEC EDGAR 06/03/2026 - 04:41 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	0001604019
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 INCORPORATED
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	Sara Bonstein
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	2404	245857	216752451	06/03/2026	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			2404	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
Sara Bonstein 700 US Highway 202/206 Bridgewater NJ 08807	Common	05/13/2026	8272	961020

144: Remarks and Signature

Remarks
Date of Notice	06/03/2026
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	Sara Bonstein
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)