# EDGAR Filing Document

**Accession Number:** 0002070849
**File Stem:** 0001193125-25-274956
**Filing Date:** 2025-11
**Character Count:** 7791
**Document Hash:** 0097be83d3eb4d57e73a2076881ffbd7
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-274956.hdr.sgml**: 20251110

**ACCESSION NUMBER**: 0001193125-25-274956

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251106

**FILED AS OF DATE**: 20251110

**DATE AS OF CHANGE**: 20251110

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Rai Akshay
- **CENTRAL INDEX KEY:** 0002087877

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42934
- **FILM NUMBER:** 251468108

**MAIL ADDRESS:**
- **STREET 1:** 2180 SAND HILL ROAD, STE. 100
- **CITY:** MENLO PARK
- **STATE:** CA
- **ZIP:** 94025
**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

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Rai Akshay<br><sub>(Last) (First) (Middle)</sub><br>2180 SAND HILL ROAD, STE. 100<br><sub>(Street)</sub><br>MENLO PARK, CA 94025<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-06 | **5. 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>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>BillionToOne, Inc. [ BLLN ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<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

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2025-11-06 |  | A |  | 8333<sup>(1)</sup> | A | $0 | 8333 | D |  |
| Common Stock | 2025-11-07 |  | C<sup>(2)(3)</sup> |  | 2676 | A | <sup>(3)</sup> | 11009 | D |  |
| Common Stock | 2025-11-07 |  | C<sup>(2)(3)</sup> |  | 1784414 | A | <sup>(3)</sup> | 1784414 | I | See Footnote<sup>(4)</sup> |
| Common Stock | 2025-11-07 |  | J<sup>(5)</sup> |  | 11009 | D | <sup>(5)</sup> | 0 | D |  |
| Common Stock | 2025-11-07 |  | J<sup>(5)</sup> |  | 1784414 | D | <sup>(5)</sup> | 0 | I | See Footnote<sup>(4)</sup> |
| Class A Common Stock | 2025-11-07 |  | J<sup>(5)</sup> |  | 11009 | A | <sup>(5)</sup> | 11009 | D |  |
| Class A Common Stock | 2025-11-07 |  | J<sup>(5)</sup> |  | 1784414 | A | <sup>(5)</sup> | 1784414 | I | See Footnote<sup>(4)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Series D Convertible Preferred Stock | <sup>(3)</sup> | 2025-11-07 |  | C |  |  | 2676 | <sup>(3)</sup> | <sup>(3)</sup> | Common Stock | 2676 | <sup>(3)</sup> | 0 | D |  |
| Series D Convertible Preferred Stock | <sup>(3)</sup> | 2025-11-07 |  | C |  |  | 1784414 | <sup>(3)</sup> | <sup>(3)</sup> | Common Stock | 1784414 | <sup>(3)</sup> | 0 | I | See Footnotes<sup>(4)</sup> |

---

### Footnotes:

(1) 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.

(2) The total represents shares received upon conversion of shares of Series D Convertible Preferred Stock.

(3) 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.

(4) The reported securities are directly held by Wipro Enterprises Private Limited (Wipro), of which Mr. Rai is the nominee/investor director appointed by Wipro Enterprises Limited. Mr. Rai will not have voting or dispositive control of these securities while such securities are held by Wipro and thus disclaims beneficial ownership of such securities.

(5) 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.

**Signature:** /s/ Thomas P. Lynch, Attorney-in-Fact  
**Date:** 2025-11-10

### 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.**