SEC Form 4 · accession 0002087127-26-000004
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
Jul 13, 2026
Accepted (ET)
Jul 15, 2026 · 4:38 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 | Jul 13, 2026 | M | 10,000 | $2.80 | A | 11,000 | D | |
| Class A Common Stock | Jul 13, 2026 | M | 10,000 | $2.80 | A | 21,000 | D | |
| Class A Common StockF2 | Jul 13, 2026 | S | 1,102 | $122.9045 | D | 19,898 | D | |
| Class A Common StockF3 | Jul 13, 2026 | S | 2,477 | $123.8435 | D | 17,421 | D | |
| Class A Common StockF4 | Jul 13, 2026 | S | 2,415 | $124.8996 | D | 15,006 | D | |
| Class A Common StockF5 | Jul 13, 2026 | S | 3,185 | $125.8458 | D | 11,821 | D | |
| Class A Common StockF6 | Jul 13, 2026 | S | 821 | $126.888 | D | 11,000 | D | |
| Class A Common StockF7 | Jul 13, 2026 | S | 1,138 | $122.8428 | D | 9,862 | D | |
| Class A Common StockF8 | Jul 13, 2026 | S | 2,274 | $123.7088 | D | 7,588 | D | |
| Class A Common StockF9 | Jul 13, 2026 | S | 1,725 | $124.6538 | D | 5,863 | D | |
| Class A Common StockF10 | Jul 13, 2026 | S | 3,835 | $125.7588 | D | 2,028 | D | |
| Class A Common StockF11 | Jul 13, 2026 | S | 1,028 | $126.8952 | 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)F12 | $2.80 | Jul 13, 2026 | M | 10,000 | D | — | Jun 7, 2031 | Class A Common Stock | 10,000 | 610,000 | D |
| Stock Option (right to buy)F12 | $2.80 | Jul 13, 2026 | M | 10,000 | D | — | Jun 7, 2031 | Class A Common Stock | 10,000 | 600,000 | 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 $125.295 to $126.2805 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 $126.360 to $127.220 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 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 $122.420 to $123.3775 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 $123.440 to $124.435 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 $124.450 to $125.4325 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 $125.4525 to $126.450 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 $126.490 to $127.2981 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 $122.185 to $123.105 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 $123.2852 to $124.258 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 $124.290 to $125.240 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.