Form 4 Filing for Cyclerion Therapeutics, Inc.

Peter M. Hecht, a director and 10% owner of Cyclerion Therapeutics, Inc., reported a conversion of 351,037 shares of Series A Convertible Preferred Stock into 351,037 shares of Common Stock on July 16, 2026. This conversion, acquired through a private placement on May 19, 2023, resulted in a direct post-transaction ownership of 910,240 shares of Common Stock. Additionally, Hecht reported the cancellation of all previously held options to purchase Common Stock. He also disclaims beneficial ownership of 24 shares of Common Stock held in each of three separate trusts for his children, where his spouse serves as trustee. The total number of shares held following these transactions is 910,240 shares of Common Stock directly, and 72 shares indirectly through the trusts.