BillionToOne CTO sells shares, exercises options
Sentiment and the balance of points
Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.
Form Type
4
Rhea-AI Filing Summary
BillionToOne, Inc. Chief Technology Officer and director David Tsao reported multiple open-market sales of Class A Common Stock on July 13, 2026, totaling 20,000 shares at weighted-average prices, with underlying trade ranges from $122.185 to $127.2981 per share as detailed in footnotes. He also exercised stock options for 20,000 shares at a $2.8000 exercise price from fully vested options, pursuant to a Rule 10b5-1 trading plan adopted on March 6, 2026.
Insider Trade Summary 10b5-1
Exercise and Sale: 20,000 shares ($2.44M approx. pre-tax spread)
Exercise and Sale
14 txns
Insider
Tsao David
Role
Chief Technology Officer
Sold
20,000 shs ($2.50M)
Approx. gross sale proceeds
$2.50M
Approx. exercise cost
$56K
Approx. pre-tax spread
$2.44M
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Exercise | Stock Option (right to buy) F12 | 10,000 | $2.80 | $28K |
| Exercise | Stock Option (right to buy) F12 | 10,000 | $2.80 | $28K |
| Exercise | Class A Common Stock F1 | 10,000 | $2.80 | $28K |
| Exercise | Class A Common Stock F1 | 10,000 | $2.80 | $28K |
| Sale | Class A Common Stock F1, F2 | 1,102 | $122.9045 | $135K |
| Sale | Class A Common Stock F1, F3 | 2,477 | $123.8435 | $307K |
| Sale | Class A Common Stock F1, F4 | 2,415 | $124.8996 | $302K |
| Sale | Class A Common Stock F1, F5 | 3,185 | $125.8458 | $401K |
| Sale | Class A Common Stock F1, F6 | 821 | $126.888 | $104K |
| Sale | Class A Common Stock F1, F7 | 1,138 | $122.8428 | $140K |
| Sale | Class A Common Stock F1, F8 | 2,274 | $123.7088 | $281K |
| Sale | Class A Common Stock F1, F9 | 1,725 | $124.6538 | $215K |
| Sale | Class A Common Stock F1, F10 | 3,835 | $125.7588 | $482K |
| Sale | Class A Common Stock F1, F11 | 1,028 | $126.8952 | $130K |
Holdings After Transaction:
Stock Option (right to buy) — 600,000 contracts (Direct);
Class A Common Stock — 1,000 shares (Direct)
Footnotes (12)
- F1. The 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.
- F2. The 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.
- F3. The 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.
- F4. The 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.
- F5. The 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.
- F6. The 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.
- F7. The 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.
- F8. The 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.
- F9. The 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.
- F10. The 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.
- F11. The 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.
- F12. The options are fully vested and exercisable.
Key Figures
Shares sold: 20000 shares
Shares from option exercises: 20000 shares
Reported sale price example: 126.8952 per share
+4 more
7 metrics
Shares sold
20000 shares
Total Class A Common Stock sold on 2026-07-13
Shares from option exercises
20000 shares
Class A Common Stock underlying options exercised on 2026-07-13
Reported sale price example
126.8952 per share
One weighted-average price for a tranche of Class A shares sold
Lower bound of sale price ranges
122.185 per share
Lowest price in weighted-average sale price ranges in footnotes
Upper bound of sale price ranges
127.2981 per share
Highest price in weighted-average sale price ranges in footnotes
Option exercise price
2.8000 per share
Exercise price for Stock Option (right to buy) expiring 2031-06-07
Stock options outstanding after transaction
610000.0000 shares
Shares underlying Stock Option (right to buy) after reported exercises
Key Terms
Rule 10b5-1 trading plan, weighted average price, Stock Option (right to buy), derivative security
4 terms
Rule 10b5-1 trading plan financial
"The transactions were effected pursuant to a Rule 10b5-1 trading plan adopted"
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
weighted average price financial
"The reported price in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
Stock Option (right to buy) financial
"Security titled Stock Option (right to buy) with an exercise price of $2.8000"
derivative security financial
"Exercise or conversion of derivative security is noted in the description"
A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What insider transactions did BillionToOne (BLLN) report for David Tsao on July 13, 2026?
On July 13, 2026, CTO David Tsao reported selling 20,000 Class A shares and exercising options for 20,000 shares. The activity combines open-market or private sales with derivative exercises, all disclosed for BillionToOne’s Class A Common Stock.
What stock options did David Tsao exercise in BillionToOne (BLLN)?
David Tsao exercised options for 20,000 shares of Class A Common Stock at an exercise price of $2.8000 per share. The options, described as fully vested and exercisable, are Stock Options (right to buy) expiring on June 7, 2031.
Was the BillionToOne (BLLN) insider trading activity under a Rule 10b5-1 plan?
Yes. The filing states the transactions were effected under a Rule 10b5-1 trading plan adopted on March 6, 2026. Such pre-arranged plans systematically schedule trades, which can reduce the significance of timing for interpreting insider intent.
How many stock options remain after David Tsao’s BillionToOne (BLLN) transactions?
After the reported option exercises, one Stock Option (right to buy) position shows 610,000.0000 shares underlying options. This figure appears as the total shares following transaction for the derivative security on July 13, 2026.
AI-generated analysis. How Rhea-AI works. Not financial advice.
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