Oguzhan Atay - Nov 5, 2025 Form 3 Insider Report for BillionToOne, Inc. (BLLN)

Role
Chairman and Chief Executive Officer Exhibit 24 - Power of Attorney, Director
Signature
/s/ Thomas P. Lynch, Attorney-in-Fact
Stock symbol
BLLN
Transactions as of
Nov 5, 2025
Transactions value $
$0
Form type
3
Date filed
11/5/2025, 09:32 PM
Next filing
Nov 12, 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Atay Oguzhan Chairman and Chief Executive Officer Exhibit 24 - Power of Attorney, Director C/O BILLIONTOONE, INC., 1035 O'BRIEN DRIVE, MENLO PARK /s/ Thomas P. Lynch, Attorney-in-Fact 2025-11-05 0002088549

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
holding BLLN Common Stock 1.97M Nov 5, 2025 Direct F1
holding BLLN Common Stock 200K Nov 5, 2025 By spouse F2, F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
holding BLLN Series A-1 Convertible Preferred Stock Nov 5, 2025 Common Stock 262K Direct F4
holding BLLN Stock Option (right to buy) Nov 5, 2025 Common Stock 640K $2.80 Direct F2, F5
holding BLLN Stock Option (right to buy) Nov 5, 2025 Common Stock 1M $20.04 Direct F2, F6
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Immediately prior to the completion of the Issuer's initial public offering of Class A common stock (the "Offering"), each share of Common Stock shall be reclassified into one share of Class A common stock and such shares of Class A common stock shall be exchanged at a 1:1 ratio for shares of Class B common stock.
F2 Immediately prior to the completion of the Offering, each share of Common Stock shall be reclassified into one share of Class A common stock.
F3 Represents shares held directly by the Reporting Person's spouse.
F4 The reported security is convertible into the Issuer's Common Stock on a one-for-one basis at any time at the holder's election and shall automatically convert into Class A common stock immediately prior to the completion of the Offering without payment of further consideration. The shares have no expiration date. Immediately prior to the completion of the Offering, such shares of Class A common stock shall be exchanged at a 1:1 ratio for shares of Class B common stock.
F5 The options are fully vested and exercisable.
F6 The options are subject to a service-based vesting requirement, which shall be satisfied over a six-year period. The options vest and become exercisable in equal monthly installments commencing on June 11, 2025, subject to the Reporting Person's continuous service with the Issuer through each such vesting date.

Remarks:

Chairman and Chief Executive Officer Exhibit 24 - Power of Attorney