Brian S. Posner - 05 Jun 2026 Form 4 Insider Report for Dyne Therapeutics, Inc. (DYN)

Reporting relationship: Director
Issuer ticker: DYN
Reported as of: 05 Jun 2026
Net transaction value: +$33,880
SEC form: 4
Accepted by SEC: 09 Jun 2026, 17:06:18 UTC
Prior SEC filing: 05 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Ron Caponigro, Attorney-in-Fact

Key filing fact

Brian S. Posner filed Form 4 for Dyne Therapeutics, Inc. (DYN) on 09 Jun 2026.

Key facts

This page summarizes Brian S. Posner's Form 4 filing for Dyne Therapeutics, Inc. (DYN).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 09 Jun 2026, 17:06.

Change

Previous filing in this sequence was filed on 05 Jun 2026.
Current net transaction value: +$33,880.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001372455 Primary reporting owner

Posner Brian S

Relationship: Director
Address: 1560 TRAPELO ROAD, WALTHAM
Signature: /s/ Ron Caponigro, Attorney-in-Fact
Signature date: 09 Jun 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

DYN transaction

Common Stock

Purchase

Transaction value: $33,880
Shares: +2,000
Change %: +8.9%
Price: $16.94
Shares after: 24,500
Date: 08 Jun 2026
Ownership: Direct

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

DYN transaction Derivative

Stock option (right to buy)

Award

Transaction value
Shares: +35,152
Change %
Price: $0.000000^*
Shares after: 35,152
Date: 05 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 35,152
Exercise price: $17.04
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 1 footnote

Footnote F1

This option was granted on June 5, 2026. The shares underlying the option are scheduled to vest in full on the earlier of (i) June 5, 2027 or (ii) the date of the Issuer's 2027 Annual Meeting of Stockholders, subject to continued service.