SEC Form 4 · accession 0002088549-26-000004
BillionToOne, Inc. · BLLN
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
Oguzhan Atay
Officer — Chairman and CEO · Director
Period of report
Jul 6, 2026
Accepted (ET)
Jul 8, 2026 · 7:06 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 6, 2026 | M | 20,000 | $2.80 | A | 20,000 | D | |
| Class A Common Stock | Jul 6, 2026 | M | 6,250 | $2.80 | A | 26,250 | D | |
| Class A Common StockF2 | Jul 6, 2026 | S | 1,320 | $118.4866 | D | 24,930 | D | |
| Class A Common StockF3 | Jul 6, 2026 | S | 3,639 | $119.365 | D | 21,291 | D | |
| Class A Common StockF4 | Jul 6, 2026 | S | 1,828 | $120.6601 | D | 19,463 | D | |
| Class A Common StockF5 | Jul 6, 2026 | S | 1,115 | $121.8364 | D | 18,348 | D | |
| Class A Common StockF6 | Jul 6, 2026 | S | 6,223 | $123.0714 | D | 12,125 | D | |
| Class A Common StockF7 | Jul 6, 2026 | S | 5,253 | $123.8094 | D | 6,872 | D | |
| Class A Common StockF8 | Jul 6, 2026 | S | 622 | $124.6144 | D | 6,250 | D | |
| Class A Common StockF2 | Jul 6, 2026 | S | 412 | $118.487 | D | 5,838 | D | |
| Class A Common StockF3 | Jul 6, 2026 | S | 1,138 | $119.3648 | D | 4,700 | D | |
| Class A Common StockF4 | Jul 6, 2026 | S | 570 | $120.6596 | D | 4,130 | D | |
| Class A Common StockF5 | Jul 6, 2026 | S | 349 | $121.8357 | D | 3,781 | D | |
| Class A Common StockF6 | Jul 6, 2026 | S | 1,945 | $123.0709 | D | 1,836 | D | |
| Class A Common StockF7 | Jul 6, 2026 | S | 1,642 | $123.8093 | D | 194 | D | |
| Class A Common StockF8 | Jul 6, 2026 | S | 194 | $124.6147 | D | 0 | D | |
| Class A Common StockF9,F10 | Jul 6, 2026 | S | 1,034 | $118.8074 | D | 186,466 | I | By spouse |
| Class A Common StockF11,F10 | Jul 6, 2026 | S | 591 | $119.6744 | D | 185,875 | I | By spouse |
| Class A Common StockF12,F10 | Jul 6, 2026 | S | 444 | $120.688 | D | 185,431 | I | By spouse |
| Class A Common StockF13,F10 | Jul 6, 2026 | S | 587 | $122.0839 | D | 184,844 | I | By spouse |
| Class A Common StockF14,F10 | Jul 6, 2026 | S | 2,323 | $123.2473 | D | 182,521 | I | By spouse |
| Class A Common StockF15,F10 | Jul 6, 2026 | S | 1,221 | $124.0448 | D | 181,300 | I | By spouse |
| Class A Common StockF10 | Jul 6, 2026 | S | 50 | $124.74 | D | 181,250 | I | By spouse |
| Class A Common StockF9,F10 | Jul 6, 2026 | S | 1,034 | $118.8071 | D | 180,216 | I | By spouse |
| Class A Common StockF11,F10 | Jul 6, 2026 | S | 591 | $119.6744 | D | 179,625 | I | By spouse |
| Class A Common StockF12,F10 | Jul 6, 2026 | S | 444 | $120.688 | D | 179,181 | I | By spouse |
| Class A Common StockF13,F10 | Jul 6, 2026 | S | 586 | $122.0845 | D | 178,595 | I | By spouse |
| Class A Common StockF14,F10 | Jul 6, 2026 | S | 2,324 | $123.2472 | D | 176,271 | I | By spouse |
| Class A Common StockF15,F10 | Jul 6, 2026 | S | 1,221 | $124.0448 | D | 175,050 | I | By spouse |
| Class A Common StockF10 | Jul 6, 2026 | S | 50 | $124.74 | D | 175,000 | I | By spouse |
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)F16 | $2.80 | Jul 6, 2026 | M | 20,000 | D | — | Jun 7, 2031 | Class A Common Stock | 20,000 | 593,750 | D |
| Stock Option (right to buy)F16 | $2.80 | Jul 6, 2026 | M | 6,250 | D | — | Jun 7, 2031 | Class A Common Stock | 6,250 | 587,500 | 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.
- F10Represents shares held by the Reporting Person's spouse.
- F11The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.305 to $120.2725 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 $120.380 to $121.020 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.
- F13The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.555 to $122.490 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.
- F14The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $122.725 to $123.720 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.
- F15The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $123.740 to $124.735 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.
- F16The 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 $118.050 to $119.020 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.
- F3The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.055 to $119.970 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.
- F4The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.225 to $121.160 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 $121.390 to $122.230 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 $122.465 to $123.450 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.
- F7The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $123.475 to $124.455 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 $124.535 to $124.735 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 $118.250 to $119.240 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.