# EDGAR Filing Document

**Accession Number:** 0002070849
**File Stem:** 0001193125-25-267665
**Filing Date:** 2025-11
**Character Count:** 13498
**Document Hash:** e83be536a2f9c430f9d0a16f42a98916
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-267665.hdr.sgml**: 20251105

**ACCESSION NUMBER**: 0001193125-25-267665

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20251105

**FILED AS OF DATE**: 20251105

**DATE AS OF CHANGE**: 20251105

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Bremner Thomas S
- **CENTRAL INDEX KEY:** 0002087538

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42934
- **FILM NUMBER:** 251455827

**MAIL ADDRESS:**
- **STREET 1:** 1 N WACKER DR.
- **STREET 2:** #2700
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BillionToOne, Inc.
- **CENTRAL INDEX KEY:** 0002070849
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-MEDICAL LABORATORIES [8071]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 811082020
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 1035 O'BRIEN DRIVE
- **CITY:** MENLO PARK
- **STATE:** CA
- **BUSINESS PHONE:** 650-460-2551

**MAIL ADDRESS:**
- **STREET 1:** 1035 O'BRIEN DRIVE
- **CITY:** MENLO PARK
- **STATE:** CA
- **ZIP:** 94025

## Ex-24

POWER OF ATTORNEY

The undersigned, hereby constitutes and appoints each of Thomas Patrick Lynch and Taylor Thomas Pollock as the undersigned's true and lawful attorneys-in-fact to:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;•complete and execute Schedules 13D and 13G in accordance with Section 13 of the Securities Exchange Act of 1934, as amended (the "<u>Exchange Act</u>"), Forms 3, 4 and 5 in accordance with Section 16 of the Exchange Act and the rules thereunder, Form 144 under Rule 144 under the Securities Act of 1933 ("Rule 144"), and in each case the rules and regulations promulgated thereunder, or any successor laws and regulations, as a consequence of the undersigned's ownership, acquisition or disposition of securities, and other forms and all amendments thereto as such attorneys-in-fact shall in their discretion determine to be required or advisable; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;•do all acts necessary in order to file such forms with the Commission, any securities exchange or national association, and such other person or agency as the attorneys-in-fact shall deem appropriate.

The undersigned hereby ratifies and confirms all that said attorneys-in-fact and agent shall do or cause to be done by virtue hereof. The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned, are not assuming any of the undersigned's responsibilities to comply with Section 13 or Section 16 of the Exchange Act or Rule 144 or any other SEC rule or regulation.

The undersigned hereby grants to each such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that each such attorney-in-fact, or each such attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein granted.

This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file Schedules 13D, 13G, Forms 3, 4 and 5 or Form 144 with respect to the undersigned's holdings of and transactions in securities, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed on September 23, 2025.

---

| | |
|:---|:---|
| By: | /s/ Thomas Bremner |
| Name: | Thomas Bremner  |

---

------

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Bremner Thomas S<br><sub>(Last) (First) (Middle)</sub><br>1 NORTH WACKER DRIVE, SUITE 2200<br><sub>(Street)</sub><br>CHICAGO, IL 60606-2807<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>BillionToOne, Inc. [ BLLN ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2025-11-05 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director   [ ] 10% Owner<br>[ ] Officer (give title below)   [ ] Other (specify below)<br>_ _ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| Series A-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 1352 | <sup>(1)</sup> | I | See footnotes<sup>(2)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 114117 | <sup>(1)</sup> | I | See footnotes<sup>(2)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 16747 | <sup>(1)</sup> | I | See footnotes<sup>(2)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 20224 | <sup>(1)</sup> | I | See footnotes<sup>(2)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 121688 | <sup>(1)</sup> | I | See footnotes<sup>(3)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 17858 | <sup>(1)</sup> | I | See footnotes<sup>(3)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 16165 | <sup>(1)</sup> | I | See footnotes<sup>(3)(9)(10)</sup> |
| Series A-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 1562 | <sup>(1)</sup> | I | See footnotes<sup>(4)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 131888 | <sup>(1)</sup> | I | See footnotes<sup>(4)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 19355 | <sup>(1)</sup> | I | See footnotes<sup>(4)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 23466 | <sup>(1)</sup> | I | See footnotes<sup>(4)(9)(10)</sup> |
| Series A-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 1864 | <sup>(1)</sup> | I | See footnotes<sup>(5)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 157404 | <sup>(1)</sup> | I | See footnotes<sup>(5)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 23100 | <sup>(1)</sup> | I | See footnotes<sup>(5)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 87550 | <sup>(1)</sup> | I | See footnotes<sup>(5)(9)(10)</sup> |
| Series A-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 652 | <sup>(1)</sup> | I | See footnotes<sup>(6)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 55091 | <sup>(1)</sup> | I | See footnotes<sup>(6)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 8084 | <sup>(1)</sup> | I | See footnotes<sup>(6)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 176245 | <sup>(1)</sup> | I | See footnotes<sup>(6)(9)(10)</sup> |
| Series A-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 5988 | <sup>(1)</sup> | I | See  footnotes<sup>(7)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 505570 | <sup>(1)</sup> | I | See footnotes<sup>(7)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 74195 | <sup>(1)</sup> | I | See footnotes<sup>(7)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 89599 | <sup>(1)</sup> | I | See footnotes<sup>(7)(9)(10)</sup> |
| Series A-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 1078 | <sup>(1)</sup> | I | See footnotes<sup>(8)(9)(10)</sup> |
| Series C Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 91003 | <sup>(1)</sup> | I | See footnotes<sup>(8)(9)(10)</sup> |
| Series C-1 Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 13355 | <sup>(1)</sup> | I | See footnotes<sup>(8)(9)(10)</sup> |
| Series D Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 122072 | <sup>(1)</sup> | I | See footnotes<sup>(8)(9)(10)</sup> |

---

### Footnotes:

(1) 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 closing of the Issuer's initial public offering of Class A common stock without payment of further consideration. The shares have no expiration date.

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

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

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

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

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

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

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

(9) 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,

(10) (Continued from footnote 9)  may be deemed to beneficially own the shares held by Lumyna. 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.

**Remarks:**
Exhibit 24 - Power of Attorney

**Signature:** /s/ Thomas P. Lynch, Attorney-in-Fact  
**Date:** 2025-11-05

### Remarks:

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.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**