FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Nomads Partnership (Last) (First) (Middle) SQUARE VICTORIA REGINA 1 (Street) SINT-JOOST-TEN-NODE 1210 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 09/30/2026	3. Issuer Name and Ticker or Trading Symbol BillionToOne, Inc. [ BLLN ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Class A Common Stock	27,544 (1)	D (2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares received as a pro rata distribution in kind, for no consideration, on September 30, 2026 from Fifty Years Deep, LP, of which Nomads Partnership is a non-managing limited partner. Such pro rata distribution in kind was made in accordance with the exemption afforded by Rule 16a-9 of the Securities Exchange Act of 1934, as amended.

2. The reported security is directly held by Nomads Partnership. Hummingbird Ventures Management NV is the managing member of Nomads Partnership and, as a result, may be deemed to beneficially own shares held by Nomads Partnership. Firat 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 Nomads Partnership. The Reporting Persons disclaim beneficial ownership of these shares except to the extent of their pecuniary interests therein.

	HUMMINGBIRD VENTURES MANAGEMENT NV By: 49/9 CommV, its Director By: /s/ Lukas Decoster, Permanent Representative	10/30/2026
	** Signature of Reporting Person	Date
	NOMADS PARTNERSHIP By: Hummingbird Ventures Management NV, its Manager By: /s/ Firat Ileri, Permanent Representative	10/30/2026
	** Signature of Reporting Person	Date
	/s/ Firat Ileri	10/30/2026
	** Signature of Reporting Person	Date
	/s/ Barend Van den Brande	10/30/2026
	** Signature of Reporting Person	Date
	/s/ Lukas Decoster	10/30/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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