BillionToOne (BLLN) CTO Tsao sold 20,000 shares for $2.18M at an average $109.24 under a 10b5-1 plan
CTO David Tsao exercised 20,000 options at $2.80 and sold 20,000 shares at ~$109.24 under a 10b5-1 plan ($2.18M).
Insider transactions reported
David Tsao (Chief Technology Officer at BillionToOne Inc., BLLN) reported that they sold 20,000 shares for $2.18M at an average $109.24, and acquired 20,000 shares at $2.80 on Nov 2, 2026. After these transactions the filing shows 1,000 shares held directly.
- Reporting person
- Tsao David
- Role
- Chief Technology Officer
| Date | Type | Security | Shares | Price | Value | Held after |
|---|---|---|---|---|---|---|
| Nov 2, 2026 | Exercise or conversion of a derivative (M) | Class A Common Stock1 | +20,000 | avg $2.80 | $56K | 21,000 direct |
| Nov 2, 2026 | Open-market sale (S) | Class A Common Stock1, 2, 3, ... | -20,000 | avg $109.24 | $2.18M | 1,000 direct |
Options and other derivatives
| Date | Type | Security | Shares | Price | Value | Held after |
|---|---|---|---|---|---|---|
| Nov 2, 2026 | Exercise or conversion of a derivative (M) | Stock Option (right to buy)On 20,000 Class A Common Stock14 | -20,000 | avg $2.80 | $56K | 516,667 direct |
Holdings before and after
- Stock Option (right to buy): 536,667 to 516,667 direct
Footnotes from the filing
- 1. The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 5, 2026.
- 2. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $106.620 to $107.595 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.
- 14. The options are fully vested and exercisable.
Transaction codes in this filing
- Open-market sale:
- Code S marks a sale in the open market or a private deal. The insider received cash for these securities.
- Exercise or conversion of a derivative:
- Code M marks the exercise or conversion of an option or other derivative under an exempt plan.
FAQ
What did Tsao report in this BLLN Form 4?
David Tsao (Chief Technology Officer at BillionToOne Inc., BLLN) reported that they sold 20,000 shares for $2.18M at an average $109.24, and acquired 20,000 shares at $2.80 on Nov 2, 2026. After these transactions the filing shows 1,000 shares held directly.
How many BLLN shares does Tsao hold after this filing?
The filing shows 1,000 shares held directly after the reported transactions. Form 4 reports only the positions it lists, so this may not be every holding.
Was this BLLN insider sale made under a 10b5-1 plan?
The filing's footnotes mention a Rule 10b5-1 trading plan. Such a plan sets the terms of future trades in advance.
What does transaction code S mean on an SEC Form 4?
Code S marks a sale in the open market or a private deal. The insider received cash for these securities.
Historical context for BLLN
Across the 28 sessions after earlier BLLN headlines, the stock closed higher 14 times and lower 14 times, with a median move of 4.1% in either direction. This shows timing only: many things move a stock in a session, and these figures do not show that any headline caused a move.
| Session | Earlier headline | BLLN | SPY |
|---|---|---|---|
| Nov 5, 2026 | BillionToOne Reports Third Quarter 2026 Results and Raises 2026 Revenue Guidance | -1.3% | -4.4% |
| Oct 27, 2026 | BillionToOne to Participate in Two Upcoming Investor Conferences | +2.3% | +0.6% |
| Oct 14, 2026 | BillionToOne to Report Third Quarter 2026 Financial Results on November 4, 2026 | +3.6% | -1.1% |
| Oct 7, 2026 | BillionToOne’s Tissue-Free Northstar Response® Demonstrates On-Par to Superior Cancer Treatment Monitoring vs. Tumor-Informed Assay, New Peer-Reviewed Study Finds | -4.2% | -0.2% |
| Sep 3, 2026 | BillionToOne to Participate in the Wells Fargo 21st Annual Healthcare Conference | +3.5% | +1.0% |
| Sep 2, 2026 | Canaccord Genuity initiated coverage on BillionToOne with a new price target | +4.1% | +0.4% |
Earlier insider filings at BLLN
- Oct 30, 2026Chairman and CEO Atay Oguzhan sold $1,298,000 worth of shares (11,000 units at $118.00) as part of a pre-agreed trading plan (SEC Form 4)
- Oct 19, 2026SEC Form 4 filed by BillionToOne Inc.
- Oct 16, 2026Chairman and CEO Atay Oguzhan sold $1,090,575 worth of shares (11,000 units at $99.14) as part of a pre-agreed trading plan (SEC Form 4)
- Oct 14, 2026Chairman and CEO Atay Oguzhan sold $1,823,450 worth of shares (19,334 units at $94.31) as part of a pre-agreed trading plan (SEC Form 4)
- Oct 13, 2026SEC Form 4 filed by BillionToOne Inc.
Keep researching BLLN
- BLLN insider tradesEvery buy and sale reported by BillionToOne Inc. officers, directors and large holders.
- What is Form 4?The SEC filing that reports a change in an insider's holdings, such as a purchase, sale, option exercise or grant, generally within two business days.
- Form 4 explainedForm 4 is the SEC filing that discloses when officers, directors and 10% owners buy or sell company stock, due within 2 business days. Learn every key field and code.
- Insider trading trackerThe latest insider buys and sales across every stock.
- BLLN earnings historyPast BillionToOne Inc. earnings releases, newest first.
- BLLN financial statementsRevenue, profit, cash flow and balance sheet from BillionToOne Inc.'s SEC filings.
- Market cap
- 30-day
- Sector
- Health Care
- Industry
- Medical Specialities
- Listed since
- 2025
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