🕵️ Cyclerion Therapeutics, Inc. ($CYCN)
SEC insider & ownership activity, last 12 months · CIK 1755237 · every row links its SEC filing
Insiders were quiet over the last 12 months – no open-market buys or sells. No red-flag 8-Ks in the window.
Insider flow
0 buyers, $0 (0 lots) · 0 sellers, $0 (0 lots)
No open-market insider transactions in the last 12 months.
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Fairmount Funds Management LLC | 20.0% | 13D | Sep 8, 2026 | filing ↗ | |
| Tomas Kiselak | 20.0% | 13D | Sep 8, 2026 | filing ↗ | |
| Peter Evan Harwin | 20.0% | 13D | Sep 8, 2026 | filing ↗ | |
| Peter M. Hecht | 19.4% | 13D | Jul 16, 2026 | filing ↗ | |
| Fairmount Healthcare Fund II L.P. | 15.2% | 13D | Sep 8, 2026 | filing ↗ | |
| FMR LLC | 15.0% | 13G | May 7, 2026 | filing ↗ | |
| Abigail P. Johnson | 15.0% | 13G | May 7, 2026 | filing ↗ | |
| VHCP Management XP, LLC | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| Nimish Shah | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| Venrock Healthcare Capital Partners III, L.P. | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| VHCP Co-Investment Holdings III, LLC | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| Venrock Healthcare Capital Partners EG, L.P. | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| VHCP Management III, LLC | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| VHCP Management EG, LLC | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| Bong Y. Koh | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| Venrock Healthcare Capital Partners XP, L.P. | 9.9% | 13D | Sep 8, 2026 | filing ↗ | |
| Balyasny Asset Management L.P. | 7.3% | 13G | Aug 14, 2026 | filing ↗ | |
| BAM GP LLC | 7.3% | 13G | Aug 14, 2026 | filing ↗ | |
| Balyasny Asset Management Holdings LP | 7.3% | 13G | Aug 14, 2026 | filing ↗ | |
| Dames GP LLC | 7.3% | 13G | Aug 14, 2026 | filing ↗ | |
| Dmitry Balyasny | 7.3% | 13G | Aug 14, 2026 | filing ↗ | |
| ADAR1 Capital Management, LLC | 7.0% | 13G | Aug 14, 2026 | filing ↗ | |
| Daniel Schneeberger | 7.0% | 13G | Aug 14, 2026 | filing ↗ | |
| Wellington Biomedical Innovation Master Investors (CAYMAN) II, L.P. | 6.1% | 13G | Sep 16, 2026 | filing ↗ | |
| J. Wood Capital Advisors LLC | 5.4% | 13G | Oct 17, 2025 | filing ↗ | |
| Jason Wood | 5.4% | 13G | Oct 17, 2025 | filing ↗ | |
| Fairmount Healthcare Co-Invest VI L.P. | exited | 13D | Sep 8, 2026 | filing ↗ |
Planned insider sales (Form 144)
No sale notices filed in the last 12 months.
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Material agreement (1.01) | Sep 8, 2026 | filing ↗ |
| Acquisition or disposition (2.01) | Sep 8, 2026 | filing ↗ |
| Earnings (2.02) | Sep 8, 2026 | filing ↗ |
| Unregistered equity sale (3.02) | Sep 8, 2026 | filing ↗ |
| Material Modifications to Rights of Security Holders (3.03) | Sep 8, 2026 | filing ↗ |
| Change of control (5.01) | Sep 8, 2026 | filing ↗ |
| Officer/director changes (5.02) | Sep 8, 2026 | filing ↗ |
| Charter/bylaw changes (5.03) | Sep 8, 2026 | filing ↗ |
| Amendments to the Registrant's Code of Ethics (5.05) | Sep 8, 2026 | filing ↗ |
| Change in Shell Company Status (5.06) | Sep 8, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Sep 8, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Sep 8, 2026 | filing ↗ |
| Shareholder vote (5.07) | Aug 26, 2026 | filing ↗ |
| Other events (8.01) | Aug 26, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 26, 2026 | filing ↗ |
| Other events (8.01) | Aug 25, 2026 | filing ↗ |
| Material agreement (1.01) | Apr 1, 2026 | filing ↗ |
| Change of control (5.01) | Apr 1, 2026 | filing ↗ |
| Officer/director changes (5.02) | Apr 1, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Apr 1, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Apr 1, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Feb 17, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 17, 2026 | filing ↗ |
| Material agreement (1.01) | Jan 3, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 3, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 3, 2026 | filing ↗ |
| Other events (8.01) | Dec 1, 2025 | filing ↗ |
| Material agreement (1.01) | Sep 19, 2025 | filing ↗ |
| Reg FD disclosure (7.01) | Sep 19, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Sep 19, 2025 | filing ↗ |