Notice of Proposed Sale · 144
BillionToOne, Inc.
BLLNNASDAQEQUITYCurrent
Notice of Proposed Sale
Structured filing — 144
primary_doc.xml
Notice of proposed sale. The proposed amounts below do not establish that a sale occurred.
Proposed-sale notice
- Issuer
- BillionToOne, Inc.
- Issuer CIK
- 0002070849
- SEC file number
- 001-42934
- Phone
- 650-460-2551
- Person for whose account securities are to be sold
- Tsao David
- Relationships to issuer
- Officer · Director
- Street
- 1035 O'BRIEN DRIVE
- City
- MENLO PARK
- State / country code
- CA
- Postal code
- 94025
Securities proposed for sale
| Security | Proposed units | Aggregate market value | Units outstanding | Approximate sale date | Exchange | Broker / market maker |
|---|---|---|---|---|---|---|
| Class A | 3,333 | 416,625.00 | 42,644,388 | 09/24/2026 | NASDAQ | Fidelity Brokerage Services LLC |
Broker / market maker — proposed row 1, entry 1
- Name
- Fidelity Brokerage Services LLC
- Street
- 900 Salem Street
- City
- Smithfield
- State / country code
- RI
- Postal code
- 02917
Acquisition of securities to be sold
| Security | Acquired | Nature of acquisition | Acquired from | Amount acquired | Gift transaction | Payment date | Nature of payment |
|---|---|---|---|---|---|---|---|
| Class A | 09/24/2026 | Stock Option Exercise | Issuer | 3,333 | N | 09/24/2026 | Cash |
Sales reported in the preceding three months
| Seller | Security | Sale date | Amount sold | Gross proceeds |
|---|---|---|---|---|
| David Tsao | Class A | 07/13/2026 | 20,000 | 2,497,697.77 |
| Dt 2021 Irrevocable Trust | Class A | 07/13/2026 | 3,500 | 439,110.00 |
| David Tsao | Class A | 08/10/2026 | 10,000 | 928,600.00 |
| Dt 2021 Irrevocable Trust | Class A | 08/10/2026 | 3,500 | 325,010.00 |
| David Tsao | Class A | 08/25/2026 | 10,000 | 1,000,000.00 |
| David Tsao | Class A | 09/09/2026 | 20,000 | 1,975,400.00 |
| Dt 2021 Irrevocable Trust | Class A | 09/09/2026 | 1,750 | 170,695.00 |
Seller — prior-sale row 1, entry 1
- Name
- David Tsao
- Street
- 1035 OBrien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 2, entry 1
- Name
- Dt 2021 Irrevocable Trust
- Street
- 1035 OBrien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 3, entry 1
- Name
- David Tsao
- Street
- 1035 OBrien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 4, entry 1
- Name
- Dt 2021 Irrevocable Trust
- Street
- 1035 OBrien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 5, entry 1
- Name
- David Tsao
- Street
- 1035 OBrien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 6, entry 1
- Name
- David Tsao
- Street
- 1035 OBrien Drive,
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 7, entry 1
- Name
- Dt 2021 Irrevocable Trust
- Street
- 1035 OBrien Drive
- City
- Menlo
- State / country code
- CA
- Postal code
- 94025
Prior-sale reporting
- Nothing to report for the preceding three months
- N
Remarks
Sales within the past 3 months occurred in the account of the Dt 2021 Irrevocable Trust by Icontrust Llc, trustee on the account. David Tsao is an account stakeholder in the Dt 2021 Irrevocable Trust.
Notice signature
- Notice date
- 09/24/2026
- Signed
- /s/Wade Moss, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for David Tsao
- Plan adoption dates
- 06/05/2026