DYN insider buying and SEC filings, explained
Dyne Therapeutics, Inc. · CIK 1818794
Tracked: Forms 3/4/5, 8-K, NT · All filings on sec.gov
Insider activity in the last 12 months
Bought
$315K
Insiders who bought
1
Sold (not marked 10b5-1)
$48K
Planned sales (10b5-1)
$168.6M
Insider purchases and sales, last 12 months
| Traded | Type | What was filed | Source |
|---|---|---|---|
| Oct 2, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,500 shares at $16.00 ($40K), reported as a purchase (code P). Holdings up 10% to 27,000 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Oct 6, 2026, 4:15 PM ET |
| Sep 8, 2026 | Planned (10b5-1) | John Cox (CEO and Director) sold 5,658 shares at about $18.88 ($107K), marked as a 10b5-1 plan trade. Holdings down 2% to 357,507 shares. | SEC filing Filed Sep 8, 2026 |
| Sep 4–8, 2026 | Planned (10b5-1) | Johanna Friedl-Naderer (Chief Commercial Officer) sold 1,085 shares between Sep 4 and Sep 8 at about $23.42 ($25K), marked as a 10b5-1 plan trade. Holdings down 1% to 152,897 shares. | SEC filing Filed Sep 8, 2026 |
| Sep 4–8, 2026 | Planned (10b5-1) | Douglas Kerr (Chief Medical Officer) sold 5,035 shares between Sep 4 and Sep 8 at about $22.95 ($116K), marked as a 10b5-1 plan trade. Holdings down 3% to 162,564 shares. | SEC filing Filed Sep 8, 2026 |
| Aug 13, 2026 | Planned (10b5-1) | Johanna Friedl-Naderer (Chief Commercial Officer) sold 226 shares at about $26.28 ($6K), marked as a 10b5-1 plan trade. Holdings down <1% to 153,982 shares. | SEC filing Filed Aug 17, 2026 |
| Aug 13, 2026 | Planned (10b5-1) | Douglas Kerr (Chief Medical Officer) sold 1,556 shares at about $26.28 ($41K), marked as a 10b5-1 plan trade. Holdings down 1% to 167,599 shares. | SEC filing Filed Aug 17, 2026 |
| Aug 13, 2026 | Planned (10b5-1) | Erick Lucera (CFO) sold 1,797 shares at about $26.28 ($47K), marked as a 10b5-1 plan trade. Holdings down 1% to 119,766 shares. | SEC filing Filed Aug 17, 2026 |
| Aug 13–14, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 2,586,928 shares indirectly between Aug 13 and Aug 14 at about $25.20 ($65.2M), marked as a 10b5-1 plan trade. Indirect holdings down 86% to 428,946 shares. | SEC filing Filed Aug 17, 2026 |
| Aug 13, 2026 | Planned (10b5-1) | John Cox (CEO and Director) sold 4,986 shares at about $26.28 ($131K), marked as a 10b5-1 plan trade. Holdings down 1% to 363,165 shares. | SEC filing Filed Aug 17, 2026 |
| Jul 27, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 261,460 shares indirectly at about $25.51 ($6.7M), marked as a 10b5-1 plan trade. Indirect holdings down 7% to 3,586,796 shares. | SEC filing Filed Jul 29, 2026 |
| Jul 6–7, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 777,451 shares indirectly between Jul 6 and Jul 7 at about $22.97 ($17.9M), marked as a 10b5-1 plan trade. Indirect holdings down 100% to 2,962 shares. | SEC filing Filed Jul 8, 2026 |
| Jun 26–29, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 504,695 shares indirectly between Jun 26 and Jun 29 at about $21.23 ($10.7M), marked as a 10b5-1 plan trade. Indirect holdings down 34% to 975,931 shares. | SEC filing Filed Jun 30, 2026 |
| Jun 25, 2026 | Sale | Erick Lucera (CFO) sold 2,362 shares at about $20.37 ($48K). Holdings down 2% to 121,563 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 26, 2026 |
| Jun 23–25, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 267,760 shares indirectly between Jun 23 and Jun 25 at about $21.09 ($5.6M), marked as a 10b5-1 plan trade. Indirect holdings down 20% to 1,081,044 shares. | SEC filing Filed Jun 26, 2026 |
| Jun 22–23, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 263,962 shares indirectly between Jun 22 and Jun 23 at about $20.70 ($5.5M), marked as a 10b5-1 plan trade. Indirect holdings down 6% to 3,848,256 shares. | SEC filing Filed Jun 24, 2026 |
| Jun 17–18, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 84,355 shares indirectly between Jun 17 and Jun 18 at about $20.10 ($1.7M), marked as a 10b5-1 plan trade. Indirect holdings down 2% to 4,112,218 shares. | SEC filing Filed Jun 22, 2026 |
| Jun 16, 2026 | Planned (10b5-1) | Johanna Friedl-Naderer (Chief Commercial Officer) sold 145 shares at about $18.33 ($3K), marked as a 10b5-1 plan trade. Holdings down <1% to 154,208 shares. | SEC filing Filed Jun 17, 2026 |
| Jun 16, 2026 | Planned (10b5-1) | Douglas Kerr (Chief Medical Officer) sold 887 shares at about $18.33 ($16K), marked as a 10b5-1 plan trade. Holdings down 1% to 169,155 shares. | SEC filing Filed Jun 17, 2026 |
| Jun 16, 2026 | Planned (10b5-1) | John Cox (CEO and Director) sold 2,683 shares at about $18.33 ($49K), marked as a 10b5-1 plan trade. Holdings down 1% to 368,151 shares. | SEC filing Filed Jun 17, 2026 |
| Jun 8, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,000 shares at $16.94 ($34K), reported as a purchase (code P). Holdings up 9% to 24,500 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 9, 2026 |
| Jun 3, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,500 shares at $17.48 ($44K), reported as a purchase (code P). Holdings up 13% to 22,500 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 5, 2026 |
| May 26, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,000 shares at $18.21 ($36K), reported as a purchase (code P). Holdings up 11% to 20,000 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 28, 2026 |
| May 20, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,500 shares at $17.12 ($43K), reported as a purchase (code P). Holdings up 16% to 18,000 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 22, 2026 |
| May 13, 2026 | Planned (10b5-1) | Johanna Friedl-Naderer (Chief Commercial Officer) sold 228 shares at about $18.36 ($4K), marked as a 10b5-1 plan trade. Holdings down <1% to 154,353 shares. | SEC filing Filed May 14, 2026 |
| May 13, 2026 | Planned (10b5-1) | Douglas Kerr (Chief Medical Officer) sold 1,564 shares at about $18.36 ($29K), marked as a 10b5-1 plan trade. Holdings down 1% to 170,042 shares. | SEC filing Filed May 14, 2026 |
| May 13, 2026 | Planned (10b5-1) | Erick Lucera (CFO) sold 1,448 shares at about $18.36 ($27K), marked as a 10b5-1 plan trade. Holdings down 1% to 123,925 shares. | SEC filing Filed May 14, 2026 |
| May 13, 2026 | Planned (10b5-1) | John Cox (CEO and Director) sold 3,311 shares at about $18.36 ($61K), marked as a 10b5-1 plan trade. Holdings down 1% to 370,834 shares. | SEC filing Filed May 14, 2026 |
| May 4–6, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 106,723 shares indirectly between May 4 and May 6 at about $18.14 ($1.9M), marked as a 10b5-1 plan trade. Indirect holdings down 9% to 1,136,810 shares. | SEC filing Filed May 6, 2026 |
| Apr 28, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 227,337 shares indirectly at about $18.38 ($4.2M), marked as a 10b5-1 plan trade. Indirect holdings down 16% to 1,158,923 shares. | SEC filing Filed Apr 30, 2026 |
| Apr 23–27, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 384,549 shares indirectly between Apr 23 and Apr 27 at about $18.47 ($7.1M), marked as a 10b5-1 plan trade. Indirect holdings down 24% to 1,206,026 shares. | SEC filing Filed Apr 27, 2026 |
| Apr 21–22, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 10,952 shares indirectly between Apr 21 and Apr 22 at about $20.01 ($219K), marked as a 10b5-1 plan trade. Indirect holdings down <1% to 4,196,573 shares. | SEC filing Filed Apr 23, 2026 |
| Apr 20–22, 2026 | Planned (10b5-1) | Jason P Rhodes (Director) sold 834,302 shares indirectly between Apr 20 and Apr 22 at about $19.75 ($16.5M), marked as a 10b5-1 plan trade. Indirect holdings down 39% to 1,285,704 shares. | SEC filing Filed Apr 22, 2026 |
| Apr 17–20, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 337,248 shares indirectly between Apr 17 and Apr 20 at about $20.21 ($6.8M), marked as a 10b5-1 plan trade. Indirect holdings down 7% to 4,207,525 shares. | SEC filing Filed Apr 21, 2026 |
| Apr 15–16, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 99,613 shares indirectly between Apr 15 and Apr 16 at about $20.35 ($2.0M), marked as a 10b5-1 plan trade. Indirect holdings down 2% to 4,544,773 shares. | SEC filing Filed Apr 17, 2026 |
| Apr 1, 2026 | Planned (10b5-1) | Erick Lucera (CFO) sold 5,727 shares at about $18.64 ($107K), marked as a 10b5-1 plan trade. Holdings down 4% to 125,373 shares. | SEC filing Filed Apr 3, 2026 |
| Mar 30, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,000 shares at about $17.08 ($34K), reported as a purchase (code P). Holdings up 15% to 15,500 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Apr 1, 2026 |
| Mar 11, 2026 | Purchase (code P) | Brian S Posner (Director) bought 2,000 shares at $19.35 ($39K), reported as a purchase (code P). Holdings up 17% to 13,500 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Mar 13, 2026 |
| Mar 11, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 129,672 shares indirectly at about $19.52 ($2.5M), marked as a 10b5-1 plan trade. Indirect holdings down 3% to 4,644,386 shares. | SEC filing Filed Mar 13, 2026 |
| Mar 9–10, 2026 | Planned (10b5-1) | Dirk Kersten (Director) sold 688,788 shares indirectly between Mar 9 and Mar 10 at about $19.09 ($13.2M), marked as a 10b5-1 plan trade. Indirect holdings down 13% to 4,774,058 shares. | SEC filing Filed Mar 11, 2026 |
| Mar 6, 2026 | Purchase (code P) | Brian S Posner (Director) bought 3,000 shares at about $15.06 ($45K), reported as a purchase (code P). Holdings up 35% to 11,500 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Mar 10, 2026 |
| Mar 5, 2026 | Planned (10b5-1) | Johanna Friedl-Naderer (Chief Commercial Officer) sold 148 shares at $14.90 ($2K), marked as a 10b5-1 plan trade. Holdings down <1% to 154,581 shares. | SEC filing Filed Mar 6, 2026 |
| Mar 5, 2026 | Planned (10b5-1) | Douglas Kerr (Chief Medical Officer) sold 904 shares at $14.90 ($13K), marked as a 10b5-1 plan trade. Holdings down 1% to 171,606 shares. | SEC filing Filed Mar 6, 2026 |
| Mar 5, 2026 | Planned (10b5-1) | John Cox (CEO and Director) sold 2,732 shares at $14.90 ($41K), marked as a 10b5-1 plan trade. Holdings down 1% to 374,145 shares. | SEC filing Filed Mar 6, 2026 |
| Dec 5, 2025 | Planned (10b5-1) | John Cox (CEO and Director) sold 2,662 shares at about $20.72 ($55K), marked as a 10b5-1 plan trade. Holdings down 1% to 196,877 shares. | SEC filing Filed Dec 5, 2025 |
| Dec 5, 2025 | Planned (10b5-1) | Douglas Kerr (Chief Medical Officer) sold 880 shares at about $20.72 ($18K), marked as a 10b5-1 plan trade. Holdings down 1% to 87,510 shares. | SEC filing Filed Dec 5, 2025 |
| Dec 5, 2025 | Planned (10b5-1) | Johanna Friedl-Naderer (Chief Commercial Officer) sold 144 shares at about $20.72 ($3K), marked as a 10b5-1 plan trade. Holdings down <1% to 94,729 shares. | SEC filing Filed Dec 5, 2025 |
15 routine transactions (such as grants, option exercises or tax withholding) are not listed.
Cluster buys
No cluster buys in the last 12 months.
Red flags
No red flags in the last 12 months.
Key events
No key events in the last 12 months.
8-K filings, last 12 months
No 8-K filings in the last 12 months.
Red flags are objective triggers only: the item or form filed, never an opinion.
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