Form 4: BillionToOne CTO Sells Shares
Insider Transaction (Form 4)
David Tsao, Chief Technology Officer and a Director of BillionToOne, Inc., sold 20,000 shares of common stock on July 13, 2026.
Summary
- Option exercise/conversion: acquired 10,000 Class A Common Stock at $2.80 ($28,000) on July 13, 2026; holds 11,000 after (Direct).
- Option exercise/conversion: acquired 10,000 Class A Common Stock at $2.80 ($28,000) on July 13, 2026; holds 21,000 after (Direct).
- Open-market sale: disposed of 1,102 Class A Common Stock at $122.90 ($135,441) on July 13, 2026; holds 19,898 after (Direct).
- Open-market sale: disposed of 2,477 Class A Common Stock at $123.84 ($306,760) on July 13, 2026; holds 17,421 after (Direct).
- Open-market sale: disposed of 2,415 Class A Common Stock at $124.90 ($301,633) on July 13, 2026; holds 15,006 after (Direct).
- Open-market sale: disposed of 3,185 Class A Common Stock at $125.85 ($400,819) on July 13, 2026; holds 11,821 after (Direct).
- Open-market sale: disposed of 821 Class A Common Stock at $126.89 ($104,175) on July 13, 2026; holds 11,000 after (Direct).
- Open-market sale: disposed of 1,138 Class A Common Stock at $122.84 ($139,795) on July 13, 2026; holds 9,862 after (Direct).
- Open-market sale: disposed of 2,274 Class A Common Stock at $123.71 ($281,314) on July 13, 2026; holds 7,588 after (Direct).
- Open-market sale: disposed of 1,725 Class A Common Stock at $124.65 ($215,028) on July 13, 2026; holds 5,863 after (Direct).
- Open-market sale: disposed of 3,835 Class A Common Stock at $125.76 ($482,285) on July 13, 2026; holds 2,028 after (Direct).
- Open-market sale: disposed of 1,028 Class A Common Stock at $126.90 ($130,448) on July 13, 2026; holds 1,000 after (Direct).
- Option exercise/conversion: disposed of 10,000 Stock Option (right to buy) at $2.80 ($28,000) on July 13, 2026; holds 610,000 after (Direct).
- Option exercise/conversion: disposed of 10,000 Stock Option (right to buy) at $2.80 ($28,000) on July 13, 2026; holds 600,000 after (Direct).
Sentiment
Score: 4
Explanation: StockSavvy.ai views this as a mildly negative but low-conviction signal: an insider sold $2,497,698 of stock under a pre-arranged Rule 10b5-1 plan, which is typically routine.
Insider Transactions
David Tsao — Director, Officer (Chief Technology Officer)
Transaction made under a Rule 10b5-1 trading plan.
| Date | Transaction | Security | Shares | Price | Value | Held After |
|---|---|---|---|---|---|---|
| 2026-07-13 | Option exercise/conversion | Class A Common Stock | 10,000 | $3 | $28.0K | 11,000 |
| 2026-07-13 | Option exercise/conversion | Class A Common Stock | 10,000 | $3 | $28.0K | 21,000 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 1,102 | $123 | $135.4K | 19,898 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 2,477 | $124 | $306.8K | 17,421 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 2,415 | $125 | $301.6K | 15,006 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 3,185 | $126 | $400.8K | 11,821 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 821 | $127 | $104.2K | 11,000 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 1,138 | $123 | $139.8K | 9,862 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 2,274 | $124 | $281.3K | 7,588 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 1,725 | $125 | $215.0K | 5,863 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 3,835 | $126 | $482.3K | 2,028 |
| 2026-07-13 | Open-market sale | Class A Common Stock | 1,028 | $127 | $130.4K | 1,000 |
| 2026-07-13 | Option exercise/conversion | Stock Option (right to buy) | 10,000 | $3 | $28.0K | 610,000 |
| 2026-07-13 | Option exercise/conversion | Stock Option (right to buy) | 10,000 | $3 | $28.0K | 600,000 |
Key Dates
| Date | Description |
|---|---|
| 2026-07-13 | Option exercise/conversion (10,000 shares) |
| 2026-07-13 | Option exercise/conversion (10,000 shares) |
| 2026-07-13 | Open-market sale (1,102 shares) |
| 2026-07-13 | Open-market sale (2,477 shares) |
| 2026-07-13 | Open-market sale (2,415 shares) |
| 2026-07-13 | Open-market sale (3,185 shares) |
| 2026-07-13 | Open-market sale (821 shares) |
| 2026-07-13 | Open-market sale (1,138 shares) |
| 2026-07-13 | Open-market sale (2,274 shares) |
| 2026-07-13 | Open-market sale (1,725 shares) |
| 2026-07-13 | Open-market sale (3,835 shares) |
| 2026-07-13 | Open-market sale (1,028 shares) |
| 2026-07-13 | Option exercise/conversion (10,000 shares) |
| 2026-07-13 | Option exercise/conversion (10,000 shares) |
Keywords
insider transaction, Form 4, BLLN, BillionToOne, Inc., bearish, David Tsao
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