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
- Atay Oguzhan
- 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 | 8,333 | 1,005,293.12 | 42,644,388 | 09/28/2026 | 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 | 09/28/2026 | Stock Option Exercise | Issuer | 8,333 | N | 09/28/2026 | Cash |
Sales reported in the preceding three months
| Seller | Security | Sale date | Amount sold | Gross proceeds |
|---|---|---|---|---|
| Oguzhan Atay | Class A | 07/06/2026 | 26,250 | 3,203,733.13 |
| Ezgi N. Akcinar Atay | Class A | 07/06/2026 | 12,500 | 1,525,645.67 |
| Atay 2021 Dynasty Trust | Class A | 07/06/2026 | 2,500 | 300,000.00 |
| Oguzhan Atay | Class A | 07/09/2026 | 12,500 | 1,576,276.25 |
| Oguzhan Atay | Class A | 08/03/2026 | 32,500 | 4,450,834.75 |
| Ezgi N. Akcinar Atay | Class A | 08/03/2026 | 12,500 | 1,717,125.00 |
| Atay 2021 Dynasty Trust | Class A | 08/03/2026 | 2,500 | 343,425.00 |
| Oguzhan Atay | Class A | 08/05/2026 | 15,539 | 2,331,351.91 |
| Oguzhan Atay | Class A | 09/14/2026 | 24,999 | 2,507,908.84 |
| Ezgi N. Akcinar Atay | Class A | 09/14/2026 | 5,332 | 522,536.00 |
Seller — prior-sale row 1, entry 1
- Name
- Oguzhan Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 2, entry 1
- Name
- Ezgi N. Akcinar Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 3, entry 1
- Name
- Atay 2021 Dynasty Trust
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 4, entry 1
- Name
- Oguzhan Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 5, entry 1
- Name
- Oguzhan Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 6, entry 1
- Name
- Ezgi N. Akcinar Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 7, entry 1
- Name
- Atay 2021 Dynasty Trust
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 8, entry 1
- Name
- Oguzhan Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 9, entry 1
- Name
- Oguzhan Atay
- Street
- 1035 O'Brien Drive
- City
- Menlo Park
- State / country code
- CA
- Postal code
- 94025
Seller — prior-sale row 10, entry 1
- Name
- Ezgi N. Akcinar Atay
- 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
There are sales within the past 3 months occurred in the account of Ezgi N. Akcinar Atay, who is the spouse of Oguzhan Atay. Additionally, there are sales within the past 3 months which occurred in the Atay 2021 Dynasty Trust which were made by Icontrust Llc, trustee on the account. Oguzhan Atay is an account stakeholder in the Atay 2021 Dynasty Trust.
Notice signature
- Notice date
- 09/28/2026
- Signed
- /s/Wade Moss, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Oguzhan Atay
- Plan adoption dates
- 06/05/2026