Rhodes Jason P 4

What Happened

• Jason P. Rhodes, a director of Dyne Therapeutics (DYN), disposed of a total of 777,451 shares in open-market sales on July 6–7, 2026, generating aggregate proceeds of approximately $17,858,491. Individual reported lots ranged from 5,000 to 253,039 shares at weighted-average prices between $22.79 and $23.62 (per the filing); the filing includes detailed price ranges for the multiple trade executions.
• These were sales (not purchases), and the filing notes the trades were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 19, 2026 (Footnote F1).

Key Details

• Transaction dates: July 6, 2026 and July 7, 2026.
• Reported lots/weighted-average prices and proceeds (examples): 253,039 @ $22.79 = $5,766,759; 127,182 @ $22.79 = $2,898,478; 100,019 @ $22.79 = $2,279,433; additional lots at $23.17–$23.62; total ~777,451 shares for ~$17.86M.
• Pricing notes: the filing reports weighted-average prices and supplies execution ranges (see footnotes F2, F6–F8) — full per-price breakdown is available from the issuer/SEC upon request.
• Holdings after the transaction: the provided excerpt does not state Rhodes’s remaining beneficial ownership; several lots are reported as held by Atlas Venture funds (Footnotes F3–F5, F9), and Rhodes disclaims Section 16 beneficial ownership of those fund-held shares except to the extent of any pecuniary interest.
• Timeliness: Form 4 was filed July 8, 2026 for transactions on July 6–7, 2026 — this appears to be a timely filing (Form 4 is generally due within two business days).

Context

• These sales were executed under a pre-established 10b5-1 plan, which is commonly used to schedule insider sales and reduces the implication that the sales were motivated by inside, short-term information. Sales are generally less informative than purchases for signaling insider confidence, and the presence of a 10b5-1 plan suggests routine, planned disposals.
• Many of the shares were held by venture funds affiliated with Atlas Venture; the filing’s footnotes clarify entity ownership and Rhodes’s disclaimer of beneficial ownership for those fund-held securities.