Atay Oguzhan has filed a Form 144 to sell 2,667 shares of Class A stock in BillionToOne, Inc. This filing, dated October 28, 2026, is significant as it highlights ongoing trading activity by insiders in the medical laboratories sector.

BillionToOne, Inc., incorporated in Delaware, operates within the services-medical laboratories industry. The company is listed under the Central Index Key 0002070849 and has its headquarters at 1035 O'Brien Drive, Menlo Park, California. The firm’s fiscal year ends on December 31.

The filing indicates that the shares being sold were acquired on May 1, 2024, as pre-IPO shares. Oguzhan's sale is part of a larger trend, as he has previously sold shares within the last three months, including a notable sale of 32,500 shares on August 3, 2026, yielding gross proceeds of approximately $4.45 million.

This transaction may impact various stakeholders, particularly investors and analysts who closely monitor insider trading activities. The relationship between Oguzhan and the issuer, as noted in the filing, indicates he is a member of the immediate family of an officer and director of BillionToOne.

The filing does not specify what actions will follow this sale, leaving investors to speculate on future developments.

In this filing, Atay Oguzhan is represented by Fidelity Brokerage Services LLC, which is located at 900 Salem Street, Smithfield, RI. The aggregate market value of the shares being sold is reported to be $314,706.00, and the total number of Class A shares outstanding is 42,644,388.

Oguzhan's recent sales activity is notable, as he has conducted multiple transactions in Class A shares within the past three months, totaling over 150,000 shares sold. This includes significant sales on August 3, 2026, where he sold 32,500 shares, and subsequent sales on August 5, September 14, September 28, October 12, and October 14, 2026, with gross proceeds ranging from approximately $260,000 to $2.5 million for each transaction. Additionally, his spouse, Ezgi N. Akcinar Atay, has also participated in these sales, indicating a coordinated approach to their holdings.

The filing also mentions that the sales occurred in the context of a plan adopted on June 7, 2026, which may suggest a strategic decision regarding the timing and volume of shares sold. Furthermore, the remarks section highlights that Oguzhan is an account stakeholder in the Atay 2021 Dynasty Trust, which has also sold shares during this period, indicating a broader family strategy concerning their investments in BillionToOne.