[144] Dyne Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

Dyne Therapeutics reported a Form 144 notice showing a proposed sale of 4,552 shares of Common Stock on 09/04/2025 through Stifel Nicolaus & Company on Nasdaq with an aggregate market value of $60,402. The shares were acquired as Restricted Stock Units from the issuer on 09/03/2025 (11,875 units) and 09/04/2025 (3,000 units), with payment noted as cash. The filer also disclosed a prior sale of 1,342 shares on 06/05/2025 yielding $17,911. The notice includes the seller's representation that no undisclosed material adverse information is known.

Positive

• Transparent disclosure of proposed sale details including broker, exchange, share count, and aggregate value
• Sales derived from Restricted Stock Units are explicitly identified, clarifying the source of the securities
• Prior sale history (1,342 shares on 06/05/2025 for $17,911) is provided, showing recent insider transactions

Negative

• None.

Insights

Securities Analyst

TL;DR: Routine Form 144 disclosure for executive/insider sale of RSU-derived shares; transaction sizes are small relative to public float.

The filing documents a proposed brokered sale of 4,552 common shares via Stifel with an aggregate value of $60,402, originating from recently vested restricted stock units. The disclosure also records a prior small sale of 1,342 shares generating $17,911. From an investor-information perspective, this is a standard insider liquidity event rather than a corporate operational development; it notifies the market of insider selling but does not, by itself, indicate material change to company fundamentals.

Corporate Governance Expert

TL;DR: The filing fulfills regulatory notice requirements for insider sales tied to RSU vesting and includes the required attestation about undisclosed material information.

The table specifies acquisition type as Restricted Stock Units granted by the issuer with cash payment upon sale, and lists the broker and exchange. The presence of recent RSU acquisitions followed by near-term planned sales is consistent with routine post-vesting dispositions. The statement attesting to lack of material nonpublic information is included, satisfying Form 144 representations for the seller.

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

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

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

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 Stock	Stifel Nicolaus & Company Inc 501 N Broadway St. Louis MO 63102	4552	60402.00	142263740	09/04/2025	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 Stock	09/03/2025	Restricted Stock Units	Issuer			11875	09/04/2025	Cash
Common Stock	09/04/2025	Restricted Stock Units	Issuer			3000	09/04/2025	Cash

* 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
Doug Kerr 1560 Trapelo Road Waltham MA 2451	Common Stock	06/05/2025	1342	17911.00

144: Remarks and Signature

Remarks

Date of Notice

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

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What does the Form 144 for DYN disclose about the planned sale?

It discloses a proposed sale of 4,552 common shares on 09/04/2025 via Stifel on Nasdaq with an aggregate market value of $60,402.

Where did the shares to be sold originate according to the filing?

The shares were acquired as Restricted Stock Units from the issuer on 09/03/2025 (11,875 units) and 09/04/2025 (3,000 units).

Was there any recent insider selling disclosed prior to this notice for DYN?

Yes, the filing shows a prior sale of 1,342 shares on 06/05/2025 resulting in $17,911 gross proceeds.

Which broker and exchange are named for the proposed sale in the Form 144?

The broker is Stifel Nicolaus & Company Inc, and the transaction is to occur on Nasdaq.

Does the filer make any representations about material nonpublic information?

Yes, the filer signs a representation stating they do not know any material adverse information about the issuer that has not been publicly disclosed.