Dyne Therapeutics's three largest insider shareholders as of September 29, 2026 are Venture Fund Xi, L.P. Atlas (TenPercentOwner, 6.56Mn shares), Dirk Kersten (Director, 3.59Mn shares), Venture Opportunity Fund I, L.P. Atlas (TenPercentOwner, 2.31Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Venture Fund Xi, L.P. Atlas | TenPercentOwner | 5,698,091 | 864,487 | 6,562,578 | 41.3% | 28 Feb, 2024 |
| 2 | Dirk Kersten | Director | 0 | 3,586,796 | 3,586,796 | 22.6% | 29 Jul, 2026 |
| 3 | Venture Opportunity Fund I, L.P. Atlas | TenPercentOwner | 1,458,691 | 847,388 | 2,306,079 | 14.5% | 05 Mar, 2024 |
| 4 | Venture Opportunity Fund Ii, L.P. Atlas | TenPercentOwner | 934,581 | 0 | 934,581 | 5.9% | 14 Dec, 2022 |
| 5 | Joshua T Brumm | Ceo President | 537,998 | 0 | 537,998 | 3.4% | 12 Mar, 2024 |
| 6 | Jason P Rhodes | Director | 0 | 428,946 | 428,946 | 2.7% | 17 Aug, 2026 |
| 7 | John Cox | Ceo President | 357,507 | 0 | 357,507 | 2.2% | 08 Sep, 2026 |
| 8 | Oxana Beskrovnaya | Chief Scientific Officer | 195,840 | 0 | 195,840 | 1.2% | 13 Mar, 2025 |
| 9 | Douglas Kerr | Chief Medical Officer | 162,564 | 0 | 162,564 | 1.0% | 08 Sep, 2026 |
| 10 | Johanna Friedl-Naderer | Chief Commercial Officer | 152,897 | 0 | 152,897 | 1.0% | 08 Sep, 2026 |
| 11 | Wildon Farwell | Chief Medical Officer | 143,222 | 0 | 143,222 | 0.9% | 20 Aug, 2024 |
| 12 | Jonathan Mcneill | Chief Business Officer | 132,106 | 0 | 132,106 | 0.8% | 20 Aug, 2024 |
| 13 | Susanna Gatti High | Chief Operating Officer | 131,636 | 0 | 131,636 | 0.8% | 19 Sep, 2024 |
| 14 | Richard William Scalzo | Svp, Head Of Finance Admin. | 122,330 | 0 | 122,330 | 0.8% | 13 Mar, 2025 |
| 15 | Erick Lucera | Chief Financial Officer | 119,766 | 0 | 119,766 | 0.8% | 17 Aug, 2026 |
| 16 | Brian S Posner | Director | 24,500 | 0 | 24,500 | 0.2% | 09 Jun, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 04 Sep, 2026 | Johanna Friedl-Naderer | Chief Commercial Officer | Disposed S | 900 | $24.35 | $21.92K | 153,082 | Direct |
| 04 Sep, 2026 | Douglas Kerr | Chief Medical Officer | Disposed S | 3,745 | $24.35 | $91.19K | 163,854 | Direct |
| 08 Sep, 2026 | John Cox | Ceo President | Disposed S | 5,658 | $18.88 | $106.82K | 357,507 | Direct |
| 08 Sep, 2026 | Douglas Kerr | Chief Medical Officer | Disposed S | 1,290 | $18.88 | $24.36K | 162,564 | Direct |
| 08 Sep, 2026 | Johanna Friedl-Naderer | Chief Commercial Officer | Disposed S | 185 | $18.88 | $3.49K | 152,897 | Direct |
| 13 Aug, 2026 | Douglas Kerr | Chief Medical Officer | Disposed S | 1,556 | $26.28 | $40.89K | 167,599 | Direct |
| 13 Aug, 2026 | Johanna Friedl-Naderer | Chief Commercial Officer | Disposed S | 226 | $26.28 | $5.94K | 153,982 | Direct |
| 13 Aug, 2026 | Jason P Rhodes | Director | Disposed S | 268,354 | $26.20 | $7.03Mn | 3,801,128 | Indirect |
| 13 Aug, 2026 | Erick Lucera | Chief Financial Officer | Disposed S | 1,797 | $26.28 | $47.23K | 119,766 | Direct |
| 13 Aug, 2026 | John Cox | Ceo President | Disposed S | 4,986 | $26.28 | $131.03K | 363,165 | Direct |
| 13 Aug, 2026 | Jason P Rhodes | Director | Disposed S | 94,415 | $26.20 | $2.47Mn | 1,045,735 | Indirect |
| 13 Aug, 2026 | Jason P Rhodes | Director | Disposed S | 63,643 | $26.20 | $1.67Mn | 751,411 | Indirect |
| 14 Aug, 2026 | Jason P Rhodes | Director | Disposed S | 1,359,674 | $25.00 | $33.99Mn | 2,441,454 | Indirect |
| 14 Aug, 2026 | Jason P Rhodes | Director | Disposed S | 478,377 | $25.00 | $11.96Mn | 567,358 | Indirect |
| 14 Aug, 2026 | Jason P Rhodes | Director | Disposed S | 322,465 | $25.00 | $8.06Mn | 428,946 | Indirect |
| 27 Jul, 2026 | Dirk Kersten | Director | Disposed S | 256,072 | $25.50 | $6.53Mn | 3,592,184 | Indirect |
| 27 Jul, 2026 | Dirk Kersten | Director | Disposed S | 5,388 | $26.04 | $140.32K | 3,586,796 | Indirect |
| 06 Jul, 2026 | Jason P Rhodes | Director | Disposed S | 253,039 | $22.79 | $5.77Mn | 4,223,448 | Indirect |
| 06 Jul, 2026 | Jason P Rhodes | Director | Disposed S | 127,182 | $22.79 | $2.90Mn | 1,217,537 | Indirect |
| 06 Jul, 2026 | Jason P Rhodes | Director | Disposed S | 100,019 | $22.79 | $2.28Mn | 875,912 | Indirect |