[144] Dyne Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

Dyne Therapeutics Form 144 summary: This notice reports a proposed sale of 2,640 shares of Dyne common stock through Stifel Nicolaus, with an aggregate market value of $35,404.00 and an approximate sale date of 09/05/2025. The filer acquired 9,081 shares as restricted stock units from the issuer on 09/04/2025 and lists the acquisition payment type as equity compensation. The filing also discloses a prior sale by John Cox of 4,060 shares on 06/05/2025 for gross proceeds of $54,186.00. The company has 142,263,740 shares outstanding, making the proposed sale a very small fraction of total shares. The filer certifies they have no undisclosed material adverse information about the issuer.

Insights

Securities Analyst

TL;DR Insider sale of recently acquired RSUs is small relative to float but warrants monitoring for timing patterns.

The filer intends to sell 2,640 shares shortly after acquiring 9,081 restricted stock units the prior day, using a broker-dealer. The proceeds stated are modest (<$36k) versus the issuer's reported 142.3 million outstanding shares, indicating negligible direct market impact. However, the near-immediate disposition of newly vested equity can be interpreted by some investors as routine liquidity action rather than a vote of no confidence; context on a trading plan is not provided. No material undisclosed information is claimed in the certification.

Corporate Governance Expert

TL;DR Filing is a routine insider disclosure; rapid sale after RSU acquisition should be documented under company policies.

The Form 144 discloses required details for a proposed sale and prior sales. From a governance viewpoint, the proximity of acquisition (RSUs) and proposed sale suggests the filer may be monetizing compensation; companies commonly require adherence to blackout and trading-plan rules. The form does not state a 10b5-1 trading plan or plan adoption date. While not necessarily problematic, governance teams prefer written plans to mitigate insider-trading risk and signaling concerns.

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	2640	35404.00	142263740	09/05/2025	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	09/04/2025	Restricted Stock Units	Issuer			9081	09/04/2025	Equity Compensation

* 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
John Cox 1560 Trapelo Rd Waltham MA 02451	Common Stock	06/05/2025	4060	54186.00

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)