DYNE THERAPEUTICS INC DYN
COM · Common Stock · CUSIP 26818M108
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersWaltham, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($223.7k this quarter). Holder counts are more reliable. Shares outstanding: 186.7m as of 2026-07-24, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $22.19. Options: 4 managers hold calls ($1.1m notional), 6 hold puts ($4.4m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 102 |
| Q4 2022 | 114 |
| Q1 2023 | 128 |
| Q2 2023 | 119 |
| Q3 2023 | 115 |
| Q4 2023 | 125 |
| Q1 2024 | 170 |
| Q2 2024 | 194 |
| Q3 2024 | 201 |
| Q4 2024 | 201 |
| Q1 2025 | 206 |
| Q2 2025 | 199 |
| Q3 2025 | 207 |
| Q4 2025 | 233 |
| Q1 2026 | 228 |
| Q2 2026 | 246 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 113 | 88 |
| Q4 2024 | 98 | 97 |
| Q1 2025 | 127 | 86 |
| Q2 2025 | 117 | 83 |
| Q3 2025 | 146 | 65 |
| Q4 2025 | 146 | 87 |
| Q1 2026 | 136 | 103 |
| Q2 2026 | 131 | 104 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $2.5m | $3.2m | 1.31 |
| Q4 2025 | $4.4m | $8.2m | 1.87 |
| Q1 2026 | $768.7k | $4.5m | 5.82 |
| Q2 2026 | $1.1m | $4.4m | 4.22 |
Biggest buyers
| FMR LLC | Added | +2.3m |
| PRICE T ROWE ASSOCIATES INC /MD/ | Added | +1.6m |
| MARSHALL WACE, LLP | Added | +1.4m |
| Logos Global Management LP | Added | +1.1m |
| DIMENSIONAL FUND ADVISORS LP | Added | +994.9k |
| NOVO HOLDINGS A/S | New | +960.4k |
| CITADEL ADVISORS LLC | Added | +942.8k |
| STATE STREET CORP | Added | +804.5k |
| BANK OF AMERICA CORP /DE/ | Added | +790.1k |
| BlackRock, Inc. | Added | +704.5k |
Biggest sellers
| Atlas Venture Life Science Advisors, LLC | Reduced | -2.3m |
| PERCEPTIVE ADVISORS LLC | Reduced | -2.0m |
| STEMPOINT CAPITAL LP | Sold out | -1.0m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -850.0k |
| FCPM III SERVICES B.V. | Reduced | -796.1k |
| BRAIDWELL LP | Reduced | -760.4k |
| Vestal Point Capital, LP | Reduced | -625.0k |
| Fiera Capital Corp | Reduced | -590.6k |
| Squarepoint Ops LLC | Reduced | -534.1k |
| Deep Track Capital, LP | Reduced | -500.0k |
Biggest calls
| JANE STREET GROUP, LLC | Added | $424.2k19.1k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $330.9k14.9k shares |
| CITADEL ADVISORS LLC | Reduced | $257.6k11.6k shares |
| SIMPLEX TRADING, LLC | Reduced | $37.8k1.7k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $1.4m62.6k shares |
| JANE STREET GROUP, LLC | Reduced | $1.4m62.0k shares |
| Caption Management, LLC | Unchanged | $790.7k35.6k shares |
| CITADEL ADVISORS LLC | Added | $708.5k31.9k shares |
| SIMPLEX TRADING, LLC | Added | $144.4k6.5k shares |
| GROUP ONE TRADING LLC | Reduced | $17.8k800 shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| T. Rowe Price Investment Management, Inc. 13G · institution +2.5 pts · filed 2026-05-15 | 18.7% |
| Janus Henderson Group Ltd. 13G · institution -1.0 pts · filed 2026-08-13 | 7.3% |
| BlackRock, Inc. 13G · institution +1.2 pts · filed 2026-07-28 | 7.0% |
| FMR LLC 13G · institution +1.4 pts · filed 2026-08-06 | 6.8% |
Fell to 5% or below in the last year: Atlas Venture Fund XI, L.P. (2.4%, 2026-08-13), VANGUARD GROUP INC (0.0%, 2026-03-26), RA CAPITAL MANAGEMENT, L.P. (0.0%, 2025-11-14)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 5 | $15.8m | $4.0m |
| Q1 2025 | 0 | — | 5 | $200.2k | $200.2k |
| Q2 2025 | 0 | — | 3 | $74.1k | $74.1k |
| Q3 2025 | 1 | $911.0k | 3 | $108.0k | $108.0k |
| Q4 2025 | 0 | — | 3 | $76.4k | $76.4k |
| Q1 2026 | 1 | $118.0k | 4 | $15.7m | $15.7m |
| Q2 2026 | 1 | $156.8k | 6 | $62.6m | $62.6m |
| Q3 2026 | 0 | — | 6 | $90.2m | $90.2m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-08 | Cox John CEO & President, director | Sold plan | $106.8k5.7k shares |
| 2026-09-08 | Kerr Douglas Chief Medical Officer | Sold plan | $24.4k1.3k shares |
| 2026-09-08 | Friedl-Naderer Johanna Chief Commercial Officer | Sold plan | $3.5k185 shares |
| 2026-09-04 | Kerr Douglas Chief Medical Officer | Sold plan | $91.2k3.7k shares |
| 2026-09-04 | Friedl-Naderer Johanna Chief Commercial Officer | Sold plan | $21.9k900 shares |
| 2026-08-14 | Rhodes Jason P Director · See footnote | Sold plan | $54.0m2.2m shares |
| 2026-08-13 | Rhodes Jason P Director · See footnote | Sold plan | $11.2m426.4k shares |
| 2026-08-13 | Cox John CEO & President, director | Sold plan | $131.0k5.0k shares |
| 2026-08-13 | Lucera Erick Chief Financial Officer | Sold plan | $47.2k1.8k shares |
| 2026-08-13 | Kerr Douglas Chief Medical Officer | Sold plan | $40.9k1.6k shares |
| 2026-08-13 | Friedl-Naderer Johanna Chief Commercial Officer | Sold plan | $5.9k226 shares |
| 2026-07-27 | Kersten Dirk Director · See footnote | Sold plan | $6.7m261.5k shares |
| 2026-07-07 | Rhodes Jason P Director · See footnote | Sold plan | $6.9m297.2k shares |
| 2026-07-06 | Rhodes Jason P Director · See footnote | Sold plan | $10.9m480.2k shares |
| 2026-06-29 | Rhodes Jason P Director · See footnote | Sold plan | $4.1m195.4k shares |
| 2026-06-26 | Rhodes Jason P Director · See footnote | Sold plan | $6.6m309.3k shares |
| 2026-06-25 | Rhodes Jason P Director · See footnote | Sold plan | $508.5k24.1k shares |
| 2026-06-25 | Lucera Erick Chief Financial Officer | Sold | $48.1k2.4k shares |
| 2026-06-24 | Rhodes Jason P Director · See footnote | Sold plan | $2.0m95.9k shares |
| 2026-06-23 | Rhodes Jason P Director · See footnote | Sold plan | $3.1m147.8k shares |
| 2026-06-23 | Kersten Dirk Director · See footnote | Sold plan | $1.5m73.3k shares |
| 2026-06-22 | Kersten Dirk Director · See footnote | Sold plan | $3.9m190.7k shares |
| 2026-06-18 | Kersten Dirk Director · See footnote | Sold plan | $941.3k46.9k shares |
| 2026-06-17 | Kersten Dirk Director · See footnote | Sold plan | $754.3k37.5k shares |
| 2026-06-16 | Cox John CEO & President, director | Sold plan | $49.2k2.7k shares |
| 2026-06-16 | Kerr Douglas Chief Medical Officer | Sold plan | $16.3k887 shares |
| 2026-06-16 | Friedl-Naderer Johanna Chief Commercial Officer | Sold plan | $2.7k145 shares |
| 2026-06-08 | Posner Brian S Director | Bought | $33.9k2.0k shares |
| 2026-06-03 | Posner Brian S Director | Bought | $43.7k2.5k shares |
| 2026-05-26 | Posner Brian S Director | Bought | $36.4k2.0k shares |
The latest 30 of 52 trades.
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| T. Rowe Price Investment Management, Inc. 0.45% of their portfolio | 30.9m $686.6m | Added +126.5k |
| BlackRock, Inc. 0.00% of their portfolio | 12.4m $275.5m | Added +704.5k |
| Jupiter Topco LLC 0.11% of their portfolio | 12.0m $266.6m | First filing |
| FMR LLC 0.01% of their portfolio | 11.2m $248.9m | Added +2.3m |
| STATE STREET CORP 0.00% of their portfolio | 7.5m $165.6m | Added +804.5k |
| Orbis Allan Gray Ltd 0.53% of their portfolio | 7.0m $155.6m | Added +244.3k |
| Atlas Venture Life Science Advisors, LLC 17.14% of their portfolio | 6.8m $151.0m | Reduced -2.3m |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 6.3m $140.2m | Reduced -94.1k |
| TCG Crossover Management, LLC 2.46% of their portfolio | 4.6m $102.5m | Unchanged |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 4.0m $89.9m | Reduced -113.6k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 3.9m $87.4m | Added +1.6m |
| FCPM III SERVICES B.V. 11.39% of their portfolio | 3.8m $85.5m | Reduced -796.1k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 3.7m $83.2m | Added +239.3k |
| Vestal Point Capital, LP 1.75% of their portfolio | 3.4m $75.0m | Reduced -625.0k |
| ORBIMED ADVISORS LLC 1.36% of their portfolio | 3.2m $71.9m | Added +317.8k |
| Frazier Life Sciences Management, L.P. 1.53% of their portfolio | 3.2m $70.0m | Unchanged |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 3.2m $67.2m | Reduced -101.8k |
| ARMISTICE CAPITAL, LLC 1.90% of their portfolio | 3.1m $68.6m | Reduced -87.9k |
| PERCEPTIVE ADVISORS LLC 0.93% of their portfolio | 2.7m $59.7m | Reduced -2.0m |
| Logos Global Management LP 2.44% of their portfolio | 2.5m $56.6m | Added +1.1m |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 2.2m $49.6m | Added +790.1k |
| Venrock Adviser, LLC 1.46% of their portfolio | 2.2m $48.3m | Unchanged |
| GOLDMAN SACHS GROUP INC 0.01% of their portfolio | 2.2m $47.9m | Added +434.1k |
| Siren, L.L.C. 0.96% of their portfolio | 2.1m $47.3m | Reduced -100.0k |
| FRANKLIN RESOURCES INC 0.01% of their portfolio | 2.0m $45.1m | Added +21.7k |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 1.9m $43.2m | Added +994.9k |
| MPM BIOIMPACT LLC 2.60% of their portfolio | 1.9m $42.7m | Added +513.9k |
| SAMLYN CAPITAL, LLC 0.65% of their portfolio | 1.8m $39.0m | Reduced -167.8k |
| Sofinnova Investments, Inc. 1.97% of their portfolio | 1.7m $36.8m | Added +24.5k |
| Palo Alto Investors LP 5.06% of their portfolio | 1.6m $36.6m | Reduced -5.5k |
| Vivo Capital, LLC 3.16% of their portfolio | 1.6m $34.6m | Unchanged |
| Aberdeen Group plc 0.05% of their portfolio | 1.5m $34.2m | Added +109.0k |
| Deep Track Capital, LP 0.49% of their portfolio | 1.5m $33.3m | Reduced -500.0k |
| MARSHALL WACE, LLP 0.03% of their portfolio | 1.5m $33.1m | Added +1.4m |
| Polar Capital Holdings Plc 0.08% of their portfolio | 1.3m $28.6m | Reduced -72.4k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.3m $28.4m | Added +79.2k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 1.2m $26.7m | Added +43.8k |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 1.1m $25.4m | Added +942.8k |
| Saturn V Capital Management LP 3.37% of their portfolio | 1.1m $23.5m | Added +90.9k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 988.9k $22.0m | Added +41.5k |
| NOVO HOLDINGS A/S 1.24% of their portfolio | 960.4k $21.3m | New |
| Rock Springs Capital Management LP 1.02% of their portfolio | 942.2k $20.9m | Reduced -30.0k |
| BRAIDWELL LP 0.76% of their portfolio | 921.6k $20.5m | Reduced -760.4k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.18% of their portfolio | 874.1k $19.4m | Added +52.3k |
| BAKER BROS. ADVISORS LP 0.09% of their portfolio | 813.4k $18.1m | Unchanged |
| Fiera Capital Corp 0.06% of their portfolio | 790.0k $17.5m | Reduced -590.6k |
| MORGAN STANLEY 0.00% of their portfolio | 746.2k $16.6m | Reduced -182.8k |
| Artisan Partners Limited Partnership 0.02% of their portfolio | 659.8k $14.7m | Added +40.3k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 576.4k $12.8m | Added +124.7k |
| TD Asset Management Inc 0.01% of their portfolio | 548.1k $12.2m | Added +18.8k |
| ALGERT GLOBAL LLC 0.13% of their portfolio | 506.3k $11.2m | Added +51.8k |
| WASATCH ADVISORS LP 0.06% of their portfolio | 443.7k $9.9m | Unchanged |
| UBS Group AG 0.00% of their portfolio | 443.3k $9.8m | Added +62.7k |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 431.9k $9.6m | Added +273.3k |
| Clearbridge Investments, LLC 0.01% of their portfolio | 415.1k $9.2m | Added +11.9k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 409.8k $9.1m | Added +8.2k |
| ArrowMark Colorado Holdings LLC 0.37% of their portfolio | 397.2k $8.8m | Reduced -276.7k |
| Nuveen, LLC 0.00% of their portfolio | 386.8k $8.6m | Reduced -331.5k |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 360.6k $8.0m | Reduced -173.0k |
| Tetragon Partners GP Ltd 1.29% of their portfolio | 356.7k $7.9m | Added +98.5k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio | 356.0k $7.9m | Added +22.5k |
| Granahan Investment Management, LLC 0.27% of their portfolio | 338.6k $7.5m | New |
| University of Wisconsin Foundation 5.51% of their portfolio | 313.6k $7.0m | Reduced -171.2k |
| MOORE CAPITAL MANAGEMENT, LP 0.15% of their portfolio | 305.8k $6.8m | Added +227.0k |
| Squarepoint Ops LLC 0.01% of their portfolio | 300.1k $6.7m | Reduced -534.1k |
| Fisher Asset Management, LLC 0.00% of their portfolio | 298.5k $6.6m | Reduced -24.5k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 298.3k $6.6m | Added +135.3k |
| Ensign Peak Advisors, Inc 0.01% of their portfolio | 289.7k $6.4m | Reduced -206.9k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 270.0k $6.0m | Added +30.7k |
| Alyeska Investment Group, L.P. 0.01% of their portfolio | 245.3k $5.4m | New |
| Catalio Capital Management, LP 1.02% of their portfolio | 244.9k $5.4m | Reduced -38.0k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 242.4k $5.4m | Added +21.3k |
| Swiss National Bank 0.00% of their portfolio | 232.0k $5.2m | Added +3.9k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 220.7k $4.9m | Added +75.2k |
| SPHERA FUNDS MANAGEMENT LTD. 0.63% of their portfolio | 199.6k $4.4m | Added +39.0k |
| SummitTX Capital, L.P. 0.11% of their portfolio | 194.6k $4.3m | Reduced -1.5k |
| CITIGROUP INC 0.00% of their portfolio | 187.9k $4.2m | Added +150.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 183.8k $4.1m | Reduced -3.4k |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 174.5k $3.9m | Added +87.8k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 172.1k $3.1m | Added +36.1k |
| HighVista Strategies LLC 0.87% of their portfolio | 172.0k $3.8m | Reduced -11.0k |
| ALPS ADVISORS INC 0.02% of their portfolio | 167.1k $3.7m | New |
| Invesco Ltd. 0.00% of their portfolio | 164.6k $3.7m | Reduced -84.3k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.00% of their portfolio | 157.9k $3.5m | Reduced -7.0k |
| Y-Intercept (Hong Kong) Ltd 0.07% of their portfolio | 156.2k $3.5m | Added +91.0k |
| Darwin Wealth Management, LLC 0.94% of their portfolio | 155.3k $3.4m | Added +408 |
| AXXCESS WEALTH MANAGEMENT, LLC 0.05% of their portfolio | 155.3k $3.4m | New |
| Aegis Wealth Management LLC 1.57% of their portfolio | 150.0k $3.3m | Added +15.0k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.00% of their portfolio | 150.0k $3.3m | Reduced -850.0k |
| Woodline Partners LP 0.01% of their portfolio | 149.4k $3.3m | Unchanged |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 135.1k $3.0m | Reduced -4.5k |
| Schonfeld Strategic Advisors LLC 0.02% of their portfolio | 134.8k $3.0m | New |
| XTX Topco Ltd 0.04% of their portfolio | 125.8k $2.8m | Added +83.1k |
| Jain Global LLC 0.03% of their portfolio | 116.3k $2.6m | New |
| Rafferty Asset Management, LLC 0.01% of their portfolio | 115.1k $2.6m | Reduced -67.9k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 105.6k $2.3m | Added +65.5k |
| Legal & General Group Plc 0.00% of their portfolio | 97.9k $2.2m | Added +1.5k |
| SG Americas Securities, LLC 0.00% of their portfolio | 97.6k $2.2m | Reduced -15.0k |
| FIDEURAM - INTESA SANPAOLO PRIVATE BANKING S.P.A. 0.06% of their portfolio | 87.1k $1.9m | New |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 84.1k $1.9m | Reduced -184 |