BillionToOne, Inc. · Conversion · Common Stock

What does this filing report?

An SEC Form 4 filing for BillionToOne, Inc. records a conversion involving Common Stock on November 7, 2025. The reported quantity was 2,451,665. 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 A-2 Convertible Preferred Stock, Series A-6 Convertible Preferred Stock, Series B-1 Convertible Preferred Stock, Series B-2 Convertible Preferred Stock, Series C 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 HB&Q NV (HB&Q COMPARTMENT III).

F5

The reported security is directly held by Hummingbird Collective CommV.

F6

The reported security is directly held by Hummingbird Dragons CommV.

F7

The reported security is directly held by Hummingbird Opportunity Fund II CommV.

F8

The reported security is directly held by Hummingbird Ventures III CommV.

F9

Humming Bird Ventures Management NV is the managing member of Hummingbird Opportunity Fund II CommV, Hummingbird Ventures III CommV, Hummingbird Dragons CommV, Hummingbird Collective CommV, and HB&Q NV (HB&Q COMPARTMENT III) (the Hummingbird Funds) and, as a result, may be deemed to beneficially own shares held by the Hummingbird Funds. Mr. Ileri, Barend Van den Brande, and Lukas Decoster are partners of Hummingbird Ventures Management NV and may be deemed to have shared voting and investment power over the shares held by the Hummingbird Funds. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.

F10

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.