Key facts
- This page summarizes Humming Bird Ventures Management NV's Form 4 filing for BillionToOne, Inc. (BLLN).
- 25 reported transactions and 10 derivative rows are listed below.
- Accepted by SEC: 20 Jan 2026, 19:27.
Humming Bird Ventures Management NV - 07 Nov 2025 Form 4 Insider Report for BillionToOne, Inc. (BLLN)
- Reporting relationship
- 10%+ Owner
- Issuer ticker
- BLLN
- Reported as of
- 07 Nov 2025
- Net transaction value
- $0
- SEC form
- 4
- Accepted by SEC
- 20 Jan 2026, 19:27:56 UTC
- Prior SEC filing
- 20 Jan 2026
- Source filing
- View source filing
- Reporting owner signature
- Hummingbird Ventures Management NV /s/ Lukas Decoster 49/9 CommV, represented by its permanent representative Lukas Decoster, Director
Source evidence
Original filing metadata and source links for verification.
4 source fields
Reporting owner
1 detail
Key filing fact
Humming Bird Ventures Management NV filed Form 4 for BillionToOne, Inc. (BLLN) on 20 Jan 2026.
Change
- Previous filing in this sequence was filed on 20 Jan 2026.
- 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 (8)
CIK 0002099044
Primary reporting owner
Humming Bird Ventures Management NV
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- Hummingbird Ventures Management NV /s/ Lukas Decoster 49/9 CommV, represented by its permanent representative Lukas Decoster, Director
- Signature date
- 20 Jan 2026
CIK 0002099049
Hummingbird Opportunity Fund II CommV
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- /s/ Barend Van den Brande
- Signature date
- 20 Jan 2026
CIK 0002099047
Hummingbird Ventures III CommV
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- /s/ Lukas Decoster
- Signature date
- 20 Jan 2026
CIK 0002099040
Hummingbird Dragons CommV
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- Hummingbird Opportunity Fund II CommV /s/ Firat Ileri By: Hummingbird Ventures Management NV, its Manager By: Firat Ileri, Permanent Representative
- Signature date
- 20 Jan 2026
CIK 0002099041
Hummingbird Collective CommV
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- Hummingbird Ventures III CommV /s/ Firat Ileri By: Hummingbird Ventures Management NV, its Manager By: Firat Ileri, Permanent Representative
- Signature date
- 20 Jan 2026
CIK 0002099035
HB&Q NV (HB&Q COMPARTMENT III)
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- Hummingbird Dragons CommV /s/ Firat Ileri By: Hummingbird Ventures Management NV, its Manager By: Firat Ileri, Permanent Representative
- Signature date
- 20 Jan 2026
CIK 0002099027
Van den Brande Barend
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- Hummingbird Collective CommV /s/ Firat Ileri By: Hummingbird Ventures Management NV, its Manager By: Firat Ileri, Permanent Representative
- Signature date
- 20 Jan 2026
CIK 0002099021
Decoster Lukas
- Relationship
- 10%+ Owner
- Address
- SQUARE VICTORIA REGAIN 1, SINT-JOOST-TEN-NODE, BELGIUM
- Signature
- HB&Q NV /s/ Firat Ileri By: Hummingbird Ventures Management NV, its Manager By: Firat Ileri, Permanent Representative
- Signature date
- 20 Jan 2026
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
- +640,727
- Change %
- Price
- Shares after
- 640,727
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F1, F2, F3, F8
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +18,845
- Change %
- Price
- Shares after
- 18,845
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F1, F2, F4, F8
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +2,015,118
- Change %
- Price
- Shares after
- 2,015,118
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F1, F2, F5, F8
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +2,451,665
- Change %
- +1362%
- Price
- Shares after
- 2,631,664
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F1, F2, F6, F8
BLLN
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +2,580,833
- Change %
- Price
- Shares after
- 2,580,833
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F1, F2, F7, F8
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -640,727
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F3, F8, F9
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -18,845
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F4, F8, F9
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -2,015,118
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F5, F8, F9
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -2,631,664
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F6, F8, F9
BLLN
transaction
Common Stock
Other
- Transaction value
- Shares
- -2,580,833
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F7, F8, F9
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +640,727
- Change %
- Price
- Shares after
- 640,727
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F3, F8, F9
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +18,845
- Change %
- Price
- Shares after
- 18,845
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F4, F8, F9
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +2,015,118
- Change %
- Price
- Shares after
- 2,015,118
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F5, F8, F9
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +2,631,664
- Change %
- Price
- Shares after
- 2,631,664
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F6, F8, F9
BLLN
transaction
Class A Common Stock
Other
- Transaction value
- Shares
- +2,580,833
- Change %
- Price
- Shares after
- 2,580,833
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Footnotes
- F7, F8, F9
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
BLLN
transaction
Derivative
Series B-2 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -640,727
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 640,727
- Exercise price
- Footnotes
- F2, F3, F8
BLLN
transaction
Derivative
Series B-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -18,845
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 18,845
- Exercise price
- Footnotes
- F2, F4, F8
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -1,569,015
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 1,569,015
- Exercise price
- Footnotes
- F2, F5, F8
BLLN
transaction
Derivative
Series D Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -446,103
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 446,103
- Exercise price
- Footnotes
- F2, F5, F8
BLLN
transaction
Derivative
Series A-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -20,000
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 20,000
- Exercise price
- Footnotes
- F2, F6, F8
BLLN
transaction
Derivative
Series A-2 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -33,000
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 33,000
- Exercise price
- Footnotes
- F2, F6, F8
BLLN
transaction
Derivative
Series B-1 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -2,261,377
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 2,261,377
- Exercise price
- Footnotes
- F2, F6, F8
BLLN
transaction
Derivative
Series C Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -137,288
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 137,288
- Exercise price
- Footnotes
- F2, F6, F8
BLLN
transaction
Derivative
Series A-6 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -2,260,520
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 2,260,520
- Exercise price
- Footnotes
- F2, F7, F8
BLLN
transaction
Derivative
Series B-2 Convertible Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -320,363
- Change %
- -100%
- Price
- Shares after
- 0
- Date
- 07 Nov 2025
- Ownership
- See Footnotes
- Underlying class
- Common Stock
- Underlying amount
- 320,363
- Exercise price
- Footnotes
- F2, F7, F8
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 9 footnotes
Footnote F1
The total represents shares received upon conversion of shares of Series A-1 Convertible Preferred Stock, Series A-2 Convertible Preferred Stock, Series A-6 Convertible Preferred Stock, Series B-1 Convertible Preferred Stock, Series B-2 Convertible Preferred Stock, Series C Convertible Preferred Stock and/or Series D 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
The reported security is directly held by HB&Q NV (HB&Q COMPARTMENT III).
Footnote F4
The reported security is directly held by Hummingbird Collective CommV.
Footnote F5
The reported security is directly held by Hummingbird Dragons CommV.
Footnote F6
The reported security is directly held by Hummingbird Opportunity Fund II CommV.
Footnote F7
The reported security is directly held by Hummingbird Ventures III CommV.
Footnote F8
Humming Bird Ventures Management NV is the managing member of Hummingbird Opportunity Fund II CommV, Hummingbird Ventures III CommV, Hummingbird Dragons CommV, Hummingbird Collective CommV, and HB&Q NV (HB&Q COMPARTMENT III) (the Hummingbird Funds) and, as a result, may be deemed to beneficially own shares held by the Hummingbird Funds. Mr. 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 the Hummingbird Funds. The Reporting Persons disclaim beneficial ownership of these shares except to the extent of their pecuniary interests therein.
Footnote F9
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.