Sakakibara Shan Riku 4
4 · BillionToOne, Inc. · Filed Jul 13, 2026
Research Summary
AI-generated summary of this filing
BillionToOne (BLLN) CPO Sakakibara Exercises Options and Sells Shares
What Happened
Sakakibara Shan Riku, Chief Product Officer of BillionToOne (BLLN), exercised stock options to acquire 4,000 shares on July 9, 2026 and sold a total of 8,000 shares in open-market transactions the same day. Option exercises: 174 shares at $8.65 (cost $1,505) and 3,826 shares at $30.78 (1,117 / 1,355 / 1,354 lots; combined cost $117,764), for a total exercise cost of $119,269. Open-market sales: 8,000 shares sold at $125.00 each, generating $1,000,000 in gross proceeds. The filings also show the exercised derivative positions were disposed, indicating the exercised shares were promptly sold.
Key Details
- Transaction date: July 9, 2026 (reported on Form 4 filed July 13, 2026).
- Exercise details: 174 @ $8.65 ($1,505); 1,117 @ $30.78 ($34,381); 1,355 @ $30.78 ($41,707); 1,354 @ $30.78 ($41,676). Total exercised = 4,000 shares; total exercise cost = $119,269.
- Sales details: Open-market sales totaling 8,000 shares at $125.00 each = $1,000,000 gross proceeds.
- Net proceeds (approx.): $1,000,000 − $119,269 = $880,731 before taxes, broker fees and any withholdings.
- Shares owned after transaction: Not specified in the provided data.
- Footnotes: Transactions were made pursuant to a Rule 10b5-1 trading plan adopted March 6, 2026 (F1). Options were fully vested and exercisable per prior Form 3 (F2).
- Timeliness: Form 4 was filed July 13 for July 9 transactions; Form 4s are generally due within two business days, so this filing appears to have been submitted several days after the transactions.
Context
- These filings show an option exercise followed by immediate sales (often called a cashless exercise or same-day sale), a common way for insiders to cover option strike costs and tax obligations.
- Because the trades were executed under a pre-arranged 10b5-1 plan, they were likely scheduled in advance; such plans limit the ability to infer the insider’s short-term view.
- Sales by insiders are common and do not by themselves indicate company performance; purchases are often more informative for bullish signals.
Insider Transaction Report
- Exercise/Conversion
Class A Common Stock
[F1]2026-07-09$8.65/sh+174$1,505→ 208,174 total - Exercise/Conversion
Class A Common Stock
[F1]2026-07-09$30.78/sh+1,117$34,381→ 209,291 total - Exercise/Conversion
Class A Common Stock
[F1]2026-07-09$30.78/sh+1,355$41,707→ 210,646 total - Exercise/Conversion
Class A Common Stock
[F1]2026-07-09$30.78/sh+1,354$41,676→ 212,000 total - Sale
Class A Common Stock
[F1]2026-07-09$125.00/sh−4,000$500,000→ 208,000 total - Sale
Class A Common Stock
[F1]2026-07-09$125.00/sh−174$21,750→ 207,826 total - Sale
Class A Common Stock
[F1]2026-07-09$125.00/sh−1,117$139,625→ 206,709 total - Sale
Class A Common Stock
[F1]2026-07-09$125.00/sh−1,355$169,375→ 205,354 total - Sale
Class A Common Stock
[F1]2026-07-09$125.00/sh−1,354$169,250→ 204,000 total - Exercise/Conversion
Stock Option (right to buy)
[F2]2026-07-09$8.65/sh−174$1,505→ 35,826 totalExercise: $8.65Exp: 2033-01-18→ Class A Common Stock (174 underlying) - Exercise/Conversion
Stock Option (right to buy)
[F2]2026-07-09$30.78/sh−1,117$34,381→ 63,883 totalExercise: $30.78Exp: 2035-09-30→ Class A Common Stock (1,117 underlying) - Exercise/Conversion
Stock Option (right to buy)
[F2]2026-07-09$30.78/sh−1,355$41,707→ 62,528 totalExercise: $30.78Exp: 2035-09-30→ Class A Common Stock (1,355 underlying) - Exercise/Conversion
Stock Option (right to buy)
[F2]2026-07-09$30.78/sh−1,354$41,676→ 61,174 totalExercise: $30.78Exp: 2035-09-30→ Class A Common Stock (1,354 underlying)
Footnotes (2)
- [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 options are fully vested and exercisable. The terms of the underlying option grant are as previously reported on the Reporting Person's Form 3 filed on November 5, 2025.