Notice of Proposed Sale · 144/A
BillionToOne, Inc.
BLLNNASDAQEQUITYCurrent
Notice of Proposed Sale
Structured filing — 144/A
primary_doc.xml
Amendment · This filing reports the amendment as submitted.
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 | 10,000 | 928,600.00 | 42,644,388 | 08/10/2026 | 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 | 08/10/2026 | Stock Option Exercise | Issuer | 10,000 | N | 08/10/2026 | Cash |
Sales reported in the preceding three months
| Seller | Security | Sale date | Amount sold | Gross proceeds |
|---|---|---|---|---|
| David Tsao | Class A | 06/15/2026 | 20,000 | 2,045,326.00 |
| Dt 2021 Irrevocable Trust | Class A | 06/15/2026 | 3,500 | 355,145.00 |
| 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 |
Seller — prior-sale row 1, entry 1
- Name
- David Tsao
- Street
- 1035 O'Brien 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 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 3, entry 1
- Name
- David Tsao
- Street
- 1035 O'Brien 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 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Prior-sale reporting
- Nothing to report for the preceding three months
- N
Remarks
This Form 144 amends and supersedes the Form 144 filed on August 10, 2026. The Securities Sold During the Past 3 Months is corrected. 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
- 08/10/2026
- Signed
- /s/ Daniel Tucci, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for David Tsao
- Plan adoption dates
- 03/06/2026