BillionToOne, Inc. · Purchase · Class A Common Stock

What does this filing report?

An SEC Form 4 filing for BillionToOne, Inc. records a purchase involving Class A Common Stock on November 7, 2025. The reported quantity was 5,446. The filing date is November 10, 2025. This is one transaction record; amounts are not allocated among any joint reporting owners.

The acquisition category describes how securities were received. It does not by itself establish a cash purchase of common stock. Read the transaction code definitionsand the original filing before interpreting the amounts.

Filing footnotes & remarks

F1

Each restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest over three years in equal annual installments on the anniversary of November 6, 2025, subject to the Reporting Person's continuous service to the Issuer through each such vesting date.

F2

The total represents shares received upon conversion of shares of Series A-1 Convertible Preferred Stock, Series C Convertible Preferred Stock, Series C-1 Convertible Preferred Stock and/or Series D Convertible Preferred Stock.

F3

The reported security converted into the Issuer's Common Stock on a one-for-one basis automatically immediately prior to the closing of the Issuer's initial public offering of Class A common stock (the "Offering") without payment of further consideration. The shares have no expiration date.

F4

The reported security is directly held by Adams Street 2019 Direct Growth Equity Fund LP.

F5

The reported security is directly held by Adams Street 2020 Direct Growth Equity Fund LP.

F6

The reported security is directly held by Adams Street 2021 Direct Growth Equity Fund LP.

F7

The reported security is directly held by Adams Street 2022 Direct Growth Equity Fund LP.

F8

The reported security is directly held by Adams Street Private Equity Navigator Fund LLC (f/k/a Adams Street Global Private Markets Fund LP).

F9

The reported security is directly held by Adams Street Growth Equity Fund VII LP.

F10

The reported security is directly held by FCPR GF - Lumyna Private Equity World Fund.

F11

Adams Street Partners, LLC is the managing member of the general partner of each of Adams Street 2019 Direct Growth Equity Fund LP, Adams Street 2020 Direct Growth Equity Fund LP, Adams Street 2021 Direct Growth Equity Fund LP, Adams Street 2022 Direct Growth Equity Fund LP, Adams Street Growth Equity Fund VII LP, and Adams Street Private Equity Navigator Fund LLC (f/k/a Adams Street Global Private Markets Fund LP) (collectively, the U.S. Funds) and, as a result, may be deemed to beneficially own the shares held by the U.S. Funds. Furthermore, Adams Street Partners, LLC, is the Sous-Delegataire Financier of the Delegataire Financier of the management company of FCPR GF - Lumyna Private Equity World Fund (Lumyna and together with the U.S. Funds, the Funds) and, as a result, may be deemed to beneficially own the shares held by Lumyna.

F12

(Continued from footnote 11) Thomas S. Bremner, Jeffrey T. Diehl, Brian Dudley, Elisha P. Gould, Robin Murray and Fred Wang, each of whom is a partner of Adams Street Partners, LLC (or a subsidiary thereof), may be deemed to have shared voting, investment and dispositive power over the shares held by the Funds. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.

F13

Pursuant to a reclassification exempt under Rule 16b-7, each share of Common Stock was automatically reclassified into one share of Class A common stock immediately prior to the completion of the Offering.

Footnotes are reproduced as plain text from the current source filing. For the full context, read the original SEC filing.