Form 4 Filing: Ileri Firat Acquires Class A Common Stock

This Form 4 filing details a transaction by Ileri Firat, a 10% owner, director, and insider of BillionToOne, Inc. (BLLN). On June 10, 2026, Firat acquired 3,017 shares of Class A Common Stock under a restricted stock unit (RSU) grant, with a reported transaction price of $0.00. These RSUs are subject to a vesting requirement tied to the company's annual meeting or the one-year anniversary of June 10, 2026. Following this acquisition, Firat holds a total of 40,331 shares of Class A Common Stock. The filing was signed on June 11, 2026, by Thomas P. Lynch as Attorney-in-Fact.