SEC Form 4 · accession 0001577014-26-000010

Dyne Therapeutics, Inc. · DYN

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owner

Jason P Rhodes

Director

Period of report

Jun 23, 2026

Accepted (ET)

Jun 26, 2026 · 8:40 am EDT

Rule 10b5-1 plan

yes — trade under a plan

Issuer CIK

0001818794

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F2,F3	Jun 23, 2026	S	77,855	$21.13	D	4,805,639	I	See footnote
Common Stock^F2,F4	Jun 23, 2026	S	39,131	$21.13	D	1,510,157	I	See footnote
Common Stock^F2,F5	Jun 23, 2026	S	30,774	$21.13	D	1,106,036	I	See footnote
Common Stock^F6,F3	Jun 24, 2026	S	50,530	$21.02	D	4,755,109	I	See footnote
Common Stock^F6,F4	Jun 24, 2026	S	25,397	$21.02	D	1,484,760	I	See footnote
Common Stock^F6,F5	Jun 24, 2026	S	19,973	$21.02	D	1,086,063	I	See footnote
Common Stock^F7,F3	Jun 25, 2026	S	12,699	$21.10	D	4,742,410	I	See footnote
Common Stock^F7,F4	Jun 25, 2026	S	6,382	$21.10	D	1,478,378	I	See footnote
Common Stock^F7,F5	Jun 25, 2026	S	5,019	$21.10	D	1,081,044	I	See footnote
Common Stock^F8	holding	—	—		—	7,962	I	See footnote

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1Shares were sold pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 19, 2026.
F2The price reported in Column 4 is a weighted average price. These securities were sold in multiple transactions at prices ranging from $21.00 to $21.50 inclusive. The Reporting Persons undertake 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 securities sold at each separate price within the ranges set forth in footnotes (2), (6) and (7).
F3The shares are held directly by Atlas Venture Fund XI, L.P. ("Atlas Venture Fund XI"). The general partner of Atlas Venture Fund XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims Section 16 beneficial ownership of such securities held by Atlas Venture Fund XI, except to the extent of his pecuniary interest therein, if any.
F4The shares are owned directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). Atlas Venture Associates Opportunity II, LP ("AVAO II LP") is the general partner of AVOF II. Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.
F5The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF I"). The general partner of AVOF I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF I, except to the extent of his pecuniary interest therein, if any.
F6The price reported in Column 4 is a weighted average price. These securities were sold in multiple transactions at prices ranging from $21.00 to $21.13 inclusive.
F7The price reported in Column 4 is a weighted average price. These securities were sold in multiple transactions at prices ranging from $21.00 to $21.255 inclusive.
F8The shares are held directly by AVA XI LP. AVA XI LLC is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims Section 16 beneficial ownership of the securities held by AVA XI LP, except to the extent of his pecuniary interest therein, if any.