Key facts
- This page summarizes Oguzhan Atay's Form 4 filing for BillionToOne, Inc..
- 14 reported transactions and 6 derivative rows are listed below.
- Accepted by SEC: 12 Nov 2025, 18:14.
Oguzhan Atay - 07 Nov 2025 Form 4 Insider Report for BillionToOne, Inc.
- Reporting relationship
- Chairman and Chief Executive Officer, Director
- Issuer ticker
- BLLN on Nasdaq
- Reported as of
- 07 Nov 2025
- Net transaction value
- $0
- SEC form
- 4
- Accepted by SEC
- 12 Nov 2025, 18:14:36 UTC
- Prior SEC filing
- 05 Nov 2025
- Next SEC filing
- 10 Jun 2026
- Source filing
- View source filing
- Reporting owner signature
- /s/ Thomas P. Lynch, Attorney-in-Fact
Source evidence
Original filing metadata and source links for verification.
5 source fields
Reporting owner
1 detail
Key filing fact
Oguzhan Atay filed Form 4 for BillionToOne, Inc. on 12 Nov 2025.
Change
- Previous filing in this sequence was filed on 05 Nov 2025.
- Current net transaction value: $0.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (1)
CIK 0002088549
Primary reporting owner
Atay Oguzhan
- Relationship
- Chairman and Chief Executive Officer, Director
- Address
- C/O BILLIONTOONE, INC., 1035 O'BRIEN DRIVE, MENLO PARK
- Signature
- /s/ Thomas P. Lynch, Attorney-in-Fact
- Signature date
- 12 Nov 2025
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +262,434
- Change %
- Price
- Shares after
- 262,434
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F2
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -262,434
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F3
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -1,965,108
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F3
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -200,000
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- By spouse
- Footnotes
- F3, F4
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +262,434
- Change %
- Price
- Shares after
- 262,434
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F3
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +1,965,108
- Change %
- +749%
- Price
- Shares after
- 2,227,542
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F3
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +200,000
- Change %
- Price
- Shares after
- 200,000
- Date
- 07 Nov 2025
- Ownership
- By spouse
- Footnotes
- F3, F4
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- -2,227,542
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F5
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -262,434
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 262,434
- Exercise price
- Footnotes
- F2
BLLN
transaction
Derivative
Class B Common Stock
Other
- Transaction value
- $0
- Shares
- +2,227,542
- Change %
- Price
- $0.000000
- Shares after
- 2,227,542
- Date
- 07 Nov 2025
- Ownership
- Direct
- Underlying class
- Class A Common Stock
- Underlying amount
- 2,227,542
- Exercise price
- Footnotes
- F5, F6
BLLN
transaction
Derivative
Stock Option (right to buy)
Other
- Transaction value
- Shares
- -640,000
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 640,000
- Exercise price
- $2.80
- Footnotes
- F1, F7
BLLN
transaction
Derivative
Stock Option (right to buy)
Other
- Transaction value
- Shares
- +640,000
- Change %
- Price
- Shares after
- 640,000
- Date
- 07 Nov 2025
- Ownership
- Direct
- Underlying class
- Class A Common Stock
- Underlying amount
- 640,000
- Exercise price
- $2.80
- Footnotes
- F1, F7
BLLN
transaction
Derivative
Stock Option (right to buy)
Other
- Transaction value
- Shares
- -1,003,102
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 1,003,102
- Exercise price
- $20.04
- Footnotes
- F1, F8
BLLN
transaction
Derivative
Stock Option (right to buy)
Other
- Transaction value
- Shares
- +1,003,102
- Change %
- Price
- Shares after
- 1,003,102
- Date
- 07 Nov 2025
- Ownership
- Direct
- Underlying class
- Class A Common Stock
- Underlying amount
- 1,003,102
- Exercise price
- $20.04
- Footnotes
- F1, F8
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 8 footnotes
Footnote F1
The total represents shares received upon conversion of shares of Series A-1 Convertible Preferred Stock.
Footnote F2
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.
Footnote F3
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.
Footnote F4
Represents shares held by the Reporting Person's spouse.
Footnote F5
Following the reclassification of Common Stock into Class A Common Stock, these shares of Class A common stock were exchanged at a 1:1 ratio for shares of Class B common stock in a transaction previously approved by the Issuer's board of directors.
Footnote F6
Each share of Class B Common Stock is convertible into one share of Class A common stock at the option of the holder. Class B common stock will convert automatically on a one-for-one basis into shares of the Issuer's Class A common stock upon the earliest of (i) seven years from the date of filing of the amended and restated certificate of incorporation, in connection with the Offering and (ii) the date specified by a vote of the holders of Class B common stock representing a majority of the outstanding shares of Class B common stock.
Footnote F7
The options are fully vested and exercisable.
Footnote F8
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.
SEC remarks
Chairman and Chief Executive Officer