Dyne Therapeutics CCO auto-sells 145 shares for taxes

Dyne Therapeutics, Inc. Chief Commercial Officer Johanna Friedl-Naderer reported an open-market sale of 145 shares of common stock at a weighted average price of $18.33 per share.

Rhea-AI Filing Summary

Dyne Therapeutics, Inc. Chief Commercial Officer Johanna Friedl-Naderer reported an open-market sale of 145 shares of common stock at a weighted average price of $18.33 per share.

According to the disclosure, these shares were sold automatically to cover tax withholding obligations tied to the vesting of restricted stock units granted on December 4, 2024, under a restricted stock unit agreement described as a binding contract consistent with the affirmative defense under Rule 10b5-1. After this transaction, she holds 154,208 shares directly, which includes 123,678 unvested restricted stock units.

Insider Trade Summary 10b5-1

Net Seller: 145 shares

Net Sell 1 txn

Insider Friedl-Naderer Johanna

Role Chief Commercial Officer

Sold 145 shs ($3K)

Type	Security	Shares	Price	Value
Sale	Common Stock	145	$18.33	$3K

Holdings After Transaction: Common Stock — 154,208 shares (Direct)

Footnotes (3)

1. F1. 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. F2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $18.01 to $18.70, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote of this Form 4.
3. F3. Includes 123,678 unvested RSUs.

Key Figures

Shares sold: 145 shares Weighted average sale price: $18.33/share Sale price range: $18.01–$18.70/share +2 more

5 metrics

Shares sold 145 shares Open-market sale on June 16, 2026 to satisfy tax withholding

Weighted average sale price $18.33/share Common stock sale linked to RSU vesting

Sale price range $18.01–$18.70/share Multiple transactions within this range on sale date

Shares held after transaction 154,208 shares Direct holdings of CCO following reported sale

Unvested RSUs included 123,678 RSUs Unvested restricted stock units included in post-transaction total

Key Terms

restricted stock units, Rule 10b5-1, weighted average price

3 terms

restricted stock units financial

"Represents shares automatically sold ... in connection with the vesting of restricted stock units granted to the Reporting Person"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Rule 10b5-1 regulatory

"a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1"

Rule 10b5-1 is a regulation that allows company insiders to buy or sell their shares at predetermined times, even if they have access to non-public information. It acts like setting a schedule in advance for transactions, helping prevent accusations of unfair trading. This rule provides a way for insiders to plan trades transparently, giving investors confidence that these transactions are not based on hidden information.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

FAQ

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

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

Dyne Therapeutics reported that Chief Commercial Officer Johanna Friedl-Naderer sold 145 shares of common stock. The shares were sold at a weighted average price of $18.33 per share in an automatic transaction linked to restricted stock unit vesting and tax withholding.

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

No, the sale was not discretionary. The filing states the 145 shares were automatically sold to satisfy tax withholding obligations under a restricted stock unit agreement, structured as a binding contract consistent with the affirmative defense to liability under Rule 10b5-1.

What price range applied to the Dyne Therapeutics (DYN) insider share sale?

The reported weighted average sale price was $18.33 per share. Footnotes explain the 145 shares were sold in multiple transactions within a price range of $18.01 to $18.70, and detailed per-price information is available on request from the company or regulators.

How many Dyne Therapeutics (DYN) shares does the CCO hold after this transaction?

After the sale, Johanna Friedl-Naderer holds 154,208 shares of Dyne Therapeutics common stock directly. The filing notes this total includes 123,678 unvested restricted stock units, which are share-based awards that will vest over time according to their grant terms.

Why were Dyne Therapeutics (DYN) shares sold in connection with RSU vesting?

The filing explains the 145 shares were sold automatically to cover tax withholding due when restricted stock units vested. Such tax-related sales prevent the executive from needing separate cash to pay taxes triggered by the vesting of share-based compensation awards.

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

Form 4 Insider Transactions: What Each Field Means →

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Accepted by SEC EDGAR 06/17/2026 - 04:07 PM EDT Learn about SEC filing dates

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 MASSACHUSETTS 02451

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/16/2026

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

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

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

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	06/16/2026		S(1)		145	D	$18.33(2)	154,208(3)	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. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $18.01 to $18.70, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote of this Form 4.

3. Includes 123,678 unvested RSUs.

	/s/ Ron Caponigro, Attorney-in-Fact	06/17/2026
	** 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.
* Form 4: SEC 1474 (03-26)