SEC Form 4 · accession 0002087127-26-000002
BillionToOne, Inc. · BLLN
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
David Tsao
Officer — Chief Technology Officer · Director
Period of report
Jun 15, 2026
Accepted (ET)
Jun 17, 2026 · 5:47 pm EDT
Rule 10b5-1 plan
yes — trade under a plan
Issuer CIK
0002070849
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Class A Common Stock | Jun 15, 2026 | M | 10,000 | $2.80 | A | 11,000 | D | |
| Class A Common Stock | Jun 15, 2026 | M | 10,000 | $2.80 | A | 21,000 | D | |
| Class A Common StockF2 | Jun 15, 2026 | S | 1,704 | $100.3718 | D | 19,296 | D | |
| Class A Common StockF3 | Jun 15, 2026 | S | 2,361 | $101.5524 | D | 16,935 | D | |
| Class A Common StockF4 | Jun 15, 2026 | S | 2,816 | $102.7739 | D | 14,119 | D | |
| Class A Common StockF5 | Jun 15, 2026 | S | 2,889 | $103.6843 | D | 11,230 | D | |
| Class A Common StockF6 | Jun 15, 2026 | S | 230 | $104.472 | D | 11,000 | D | |
| Class A Common StockF7 | Jun 15, 2026 | S | 600 | $98.7417 | D | 10,400 | D | |
| Class A Common StockF8 | Jun 15, 2026 | S | 1,000 | $100.053 | D | 9,400 | D | |
| Class A Common StockF9 | Jun 15, 2026 | S | 2,461 | $101.3707 | D | 6,939 | D | |
| Class A Common StockF10 | Jun 15, 2026 | S | 2,978 | $102.5988 | D | 3,961 | D | |
| Class A Common StockF11 | Jun 15, 2026 | S | 2,398 | $103.6289 | D | 1,563 | D | |
| Class A Common StockF12 | Jun 15, 2026 | S | 563 | $104.3167 | D | 1,000 | D |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Stock Option (right to buy)F13 | $2.80 | Jun 15, 2026 | M | 10,000 | D | — | Jun 7, 2031 | Class A Common Stock | 10,000 | 630,000 | D |
| Stock Option (right to buy)F13 | $2.80 | Jun 15, 2026 | M | 10,000 | D | — | Jun 7, 2031 | Class A Common Stock | 10,000 | 620,000 | D |
Explanation of responses
- F1The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026.
- F10The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $101.980 to $102.970 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F11The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $103.140 to $104.130 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F12The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $104.160 to $104.540 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F13The options are fully vested and exercisable.
- F2The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $100.000 to $100.9175 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F3The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $101.120 to $102.020 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F4The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $102.185 to $103.150 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F5The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $103.250 to $104.200 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F6The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $104.360 to $104.610 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F7The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.160 to $99.080 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F8The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.840 to $100.280 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F9The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $100.860 to $101.800 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.