Atay Oguzhan 4

What Happened

• Atay Oguzhan, BillionToOne’s Chairman and CEO, exercised 12,500 options at $2.80 per share (cost $35,000) and sold a total of 12,500 shares in multiple open-market transactions on July 9, 2026, generating approximately $1,576,276 in gross proceeds (combined weighted-average sale price ≈ $126.10/share). The option grant is fully vested.
• The activity appears routine and was executed pursuant to a Rule 10b5-1 trading plan adopted March 6, 2026.

Key Details

• Transaction date: July 9, 2026 (Form 4 filed July 13, 2026 — filed 4 days after trades; Form 4 is generally due within 2 business days).
• Exercise: 12,500 shares acquired at $2.80 each (total $35,000). (Transaction code M = option exercise.)
• Sales (total 12,500 shares) — reported as separate weighted-average groups:
  • 7,489 shares at $125.43 (proceeds $939,318) — prices ranged $125.000–$125.910 (F2).
  • 2,002 shares at $126.48 (proceeds $253,221) — prices ranged $126.085–$127.040 (F3).
  • 2,657 shares at $127.44 (proceeds $338,599) — prices ranged $127.100–$128.060 (F4).
  • 352 shares at $128.23 (proceeds $45,138) — prices ranged $128.180–$128.295 (F5).
• Combined sale proceeds: ≈ $1,576,276; net proceeds (after exercise cost of $35,000 and fees/taxes) will be lower.
• Shares owned after the transactions: not disclosed in the provided filing excerpt.
• Notable footnotes: trades were effected under a Rule 10b5-1 plan (F1); the options were fully vested and exercisable (F6).

Context

• This was an exercise of vested options followed by open-market sales (a common way executives realize option value). The filing shows the exercise and sales occurred same day, consistent with a prearranged 10b5-1 plan.
• The presence of a 10b5-1 plan means the trades were pre-specified; the filing itself being several days after the trade may be late relative to the usual 2-business-day Form 4 deadline.