Anthony Pagano - 01 Jan 2026 Form 4 Insider Report for BillionToOne, Inc.

Role: Director
Signature: /s/ Thomas Lynch, Attorney-in-Fact
Issuer symbol: BLLN on Nasdaq
Transactions as of: 01 Jan 2026
Net transactions value: $0
Form type: 4
Filing time: 05 Jan 2026, 20:52:49 UTC
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Pagano Anthony	Director	C/O BILLIONTOONE, INC., 1035 O'BRIEN DRIVE, MENLO PARK	/s/ Thomas Lynch, Attorney-in-Fact	05 Jan 2026	0002101642

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	BLLN	Class A Common Stock	Award	$0	+4,896		$0.000000	4,896	01 Jan 2026	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The Reporting Person was granted restricted stock units (RSUs), which represent a contingent right to receive one share of Class A common stock for each RSU. The RSUs are subject to a service-based vesting requirement, which shall be satisfied in three equal annual installments on each anniversary of January 1, 2026, subject to the Reporting Person's continuous service with the issuer through each such anniversary.

Content

The Reporting Person was granted restricted stock units (RSUs), which represent a contingent right to receive one share of Class A common stock for each RSU. The RSUs are subject to a service-based vesting requirement, which shall be satisfied in three equal annual installments on each anniversary of January 1, 2026, subject to the Reporting Person's continuous service with the issuer through each such anniversary.