Dyne Therapeutics (DYN) CCO completes small tax-driven share sale

Rhea-AI Filing Summary

Dyne Therapeutics, Inc. Chief Commercial Officer Johanna Friedl-Naderer reported an automatic sale of 148 shares of common stock at $14.90 per share. The shares were sold to satisfy tax withholding obligations tied to the vesting of restricted stock units granted on December 4, 2024, under a pre-arranged Rule 10b5-1 "binding contract," so the transaction was not discretionary. After this sale, she beneficially owned 154,581 shares of common stock, including 129,790 unvested RSUs.

Insider Trade Summary

Net Seller: 148 shares ($2,205)

Net Sell 1 txn

Insider Friedl-Naderer Johanna

Role Chief Commercial Officer

Sold 148 shs ($2K)

Type	Security	Shares	Price	Value
Sale	Common Stock	148	$14.90	$2K

Holdings After Transaction: Common Stock — 154,581 shares (Direct)

Footnotes (1)

1. Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on December 4, 2024. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person. Includes 129,790 unvested RSUs.

Form 4 Insider Transactions: What Each Field Means →

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).

X

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^*

Friedl-Naderer Johanna

(Last) (First) (Middle)

C/O DYNE THERAPEUTICS, INC.

1560 TRAPELO ROAD

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Dyne Therapeutics, Inc. [ DYN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

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

3. Date of Earliest Transaction (Month/Day/Year)
03/05/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

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

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/05/2026		S(1)		148	D	$14.9	154,581(2)	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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on December 4, 2024. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

2. Includes 129,790 unvested RSUs.

	/s/ Ron Caponigro, Attorney-in-Fact	03/06/2026
	** 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.

FAQ

What insider transaction did Dyne Therapeutics (DYN) report for Johanna Friedl-Naderer?

Dyne Therapeutics reported that Chief Commercial Officer Johanna Friedl-Naderer automatically sold 148 shares of common stock at $14.90 per share. The sale was to cover tax withholding obligations from vesting restricted stock units granted on December 4, 2024, under a Rule 10b5-1 contract.

Was the Dyne Therapeutics (DYN) insider share sale a discretionary trade?

No, the 148-share sale by Johanna Friedl-Naderer was not discretionary. It was an automatic sale specified in a restricted stock unit agreement, structured as a Rule 10b5-1 "binding contract" to satisfy tax withholding when RSUs vested on previously agreed terms.

How many Dyne Therapeutics (DYN) shares does Johanna Friedl-Naderer own after the transaction?

Following the 148-share tax-related sale, Johanna Friedl-Naderer beneficially owned 154,581 shares of Dyne Therapeutics common stock. This total includes 129,790 unvested restricted stock units, which represent share-based compensation that will vest over time, subject to applicable conditions.

What was the price of the Dyne Therapeutics (DYN) insider share sale?

The automatic sale of 148 Dyne Therapeutics common shares by Johanna Friedl-Naderer was executed at $14.90 per share. This transaction was solely to cover tax withholding on vested RSUs and was carried out under an established Rule 10b5-1 trading arrangement.

What role does Johanna Friedl-Naderer hold at Dyne Therapeutics (DYN)?

Johanna Friedl-Naderer serves as Chief Commercial Officer at Dyne Therapeutics, Inc. Her reported Form 4 transaction reflects an automatic, tax-withholding share sale linked to vesting restricted stock units that form part of her overall equity-based compensation package.