Key facts
- This page summarizes Thomas S. Bremner's Form 4 filing for BillionToOne, Inc..
- 57 reported transactions and 27 derivative rows are listed below.
- Accepted by SEC: 10 Nov 2025, 21:38.
Thomas S. Bremner - 06 Nov 2025 Form 4 Insider Report for BillionToOne, Inc.
- Reporting relationship
- Director
- Issuer ticker
- BLLN on Nasdaq
- Reported as of
- 06 Nov 2025
- Net transaction value
- +$2,499,960
- SEC form
- 4
- Accepted by SEC
- 10 Nov 2025, 21:38:40 UTC
- Prior SEC filing
- 05 Nov 2025
- Next SEC filing
- 12 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
Thomas S. Bremner filed Form 4 for BillionToOne, Inc. on 10 Nov 2025.
Change
- Previous filing in this sequence was filed on 05 Nov 2025.
- Current net transaction value: +$2,499,960.
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 0002087538
Primary reporting owner
Bremner Thomas S
- Relationship
- Director
- Address
- 1 NORTH WACKER DRIVE, SUITE 2200, CHICAGO
- Signature
- /s/ Thomas P. Lynch, Attorney-in-Fact
- Signature date
- 10 Nov 2025
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
BLLN
transaction
Common Stock
Award
- Transaction value
- $0
- Shares
- +8,333
- Change %
- Price
- $0.000000
- Shares after
- 8,333
- Date
- 06 Nov 2025
- Ownership
- Direct
- Footnotes
- F1
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +152,440
- Change %
- Price
- Shares after
- 152,440
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F4, F11, F12
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +155,711
- Change %
- Price
- Shares after
- 155,711
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F5, F11, F12
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +176,271
- Change %
- Price
- Shares after
- 176,271
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F6, F11, F12
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +269,918
- Change %
- Price
- Shares after
- 269,918
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F7, F11, F12
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +240,072
- Change %
- Price
- Shares after
- 240,072
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F8, F11, F12
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +675,352
- Change %
- Price
- Shares after
- 675,352
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F9, F11, F12
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +277,508
- Change %
- Price
- Shares after
- 277,508
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F2, F3, F10, F11, F12
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -8,333
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -152,440
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F4, F11, F12, F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -155,711
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F5, F11, F12, F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -176,271
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F6, F11, F12, F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -269,918
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F7, F11, F12, F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -240,072
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F8, F11, F12, F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -675,352
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F9, F11, F12, F13
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -277,508
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F10, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +8,333
- Change %
- Price
- Shares after
- 8,333
- Date
- 07 Nov 2025
- Ownership
- Direct
- Footnotes
- F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +152,440
- Change %
- Price
- Shares after
- 152,440
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F4, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +155,711
- Change %
- Price
- Shares after
- 155,711
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F5, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +176,271
- Change %
- Price
- Shares after
- 176,271
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F6, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +269,918
- Change %
- Price
- Shares after
- 269,918
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F7, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +240,072
- Change %
- Price
- Shares after
- 240,072
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F8, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +675,352
- Change %
- Price
- Shares after
- 675,352
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F9, F11, F12, F13
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +277,508
- Change %
- Price
- Shares after
- 277,508
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F10, F11, F12, F13
BLLN
transaction
Class A Common Stock
Purchase
- Transaction value
- $240,960
- Shares
- +4,016
- Change %
- +2.6%
- Price
- $60.00*
- Shares after
- 156,456
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F4, F11, F12
BLLN
transaction
Class A Common Stock
Purchase
- Transaction value
- $245,040
- Shares
- +4,084
- Change %
- +2.6%
- Price
- $60.00*
- Shares after
- 159,795
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F5, F11, F12
BLLN
transaction
Class A Common Stock
Purchase
- Transaction value
- $207,720
- Shares
- +3,462
- Change %
- +2%
- Price
- $60.00*
- Shares after
- 179,733
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F6, F11, F12
BLLN
transaction
Class A Common Stock
Purchase
- Transaction value
- $326,760
- Shares
- +5,446
- Change %
- +2%
- Price
- $60.00*
- Shares after
- 275,364
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F7, F11, F12
BLLN
transaction
Class A Common Stock
Purchase
- Transaction value
- $412,020
- Shares
- +6,867
- Change %
- +2.9%
- Price
- $60.00*
- Shares after
- 246,939
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F8, F11, F12
BLLN
transaction
Class A Common Stock
Purchase
- Transaction value
- $1,067,460
- Shares
- +17,791
- Change %
- +2.6%
- Price
- $60.00*
- Shares after
- 693,143
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F9, F11, F12
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
- -1,352
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 1,352
- Exercise price
- Footnotes
- F3, F4, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -114,117
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 114,117
- Exercise price
- Footnotes
- F3, F4, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,747
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,747
- Exercise price
- Footnotes
- F3, F4, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -20,224
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 20,224
- Exercise price
- Footnotes
- F3, F4, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -121,688
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 121,688
- Exercise price
- Footnotes
- F3, F5, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -17,858
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 17,858
- Exercise price
- Footnotes
- F3, F5, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,165
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,165
- Exercise price
- Footnotes
- F3, F5, F11, F12
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -1,562
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 1,562
- Exercise price
- Footnotes
- F3, F6, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -131,888
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 131,888
- Exercise price
- Footnotes
- F3, F6, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -19,355
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 19,355
- Exercise price
- Footnotes
- F3, F6, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -23,466
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 23,466
- Exercise price
- Footnotes
- F3, F6, F11, F12
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -1,864
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 1,864
- Exercise price
- Footnotes
- F3, F7, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -157,404
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 157,404
- Exercise price
- Footnotes
- F3, F7, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -23,100
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 23,100
- Exercise price
- Footnotes
- F3, F7, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -87,550
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 87,550
- Exercise price
- Footnotes
- F3, F7, F11, F12
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -652
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 652
- Exercise price
- Footnotes
- F3, F8, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -55,091
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 55,091
- Exercise price
- Footnotes
- F3, F8, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -8,084
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 8,084
- Exercise price
- Footnotes
- F3, F8, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -176,245
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 176,245
- Exercise price
- Footnotes
- F3, F8, F11, F12
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -5,988
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 5,988
- Exercise price
- Footnotes
- F3, F9, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -505,570
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 505,570
- Exercise price
- Footnotes
- F3, F9, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -74,195
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 74,195
- Exercise price
- Footnotes
- F3, F9, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -89,599
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 89,599
- Exercise price
- Footnotes
- F3, F9, F11, F12
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -1,078
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 1,078
- Exercise price
- Footnotes
- F3, F10, F11, F12
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -91,003
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 91,003
- Exercise price
- Footnotes
- F3, F10, F11, F12
BLLN
transaction
Derivative
Series C-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -13,355
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 13,355
- Exercise price
- Footnotes
- F3, F10, F11, F12
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -122,072
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 122,072
- Exercise price
- Footnotes
- F3, F10, F11, F12
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 13 footnotes
Footnote F1
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.
Footnote F2
The total represents shares received upon conversion of shares of Series A-1 Convertible Preferred Stock, Series C Convertible Preferred Stock, Series C-1 Convertible Preferred Stock and/or Series D Convertible Preferred Stock.
Footnote F3
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 F4
The reported security is directly held by Adams Street 2019 Direct Growth Equity Fund LP.
Footnote F5
The reported security is directly held by Adams Street 2020 Direct Growth Equity Fund LP.
Footnote F6
The reported security is directly held by Adams Street 2021 Direct Growth Equity Fund LP.
Footnote F7
The reported security is directly held by Adams Street 2022 Direct Growth Equity Fund LP.
Footnote F8
The reported security is directly held by Adams Street Private Equity Navigator Fund LLC (f/k/a Adams Street Global Private Markets Fund LP).
Footnote F9
The reported security is directly held by Adams Street Growth Equity Fund VII LP.
Footnote F10
The reported security is directly held by FCPR GF - Lumyna Private Equity World Fund.
Footnote F11
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, may be deemed to beneficially own the shares held by Lumyna.
Footnote F12
(Continued from footnote 11) 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.
Footnote F13
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.