Ambiq Micro: president and COO Chen Sean Chihhsiang sold 15,000 shares

What happened

• Chen Sean Chihhsiang, president and COO, exercised options for 15,000 shares at $8.12 per share for $121,800 and sold a total of 15,000 shares in multiple open-market transactions on Oct 14, 2026 for aggregate proceeds of $772,438. The filing also reports a derivative disposition of 15,000 shares at $0.00.

Key details

• Transaction date: Oct 14, 2026; Form 4 filed Oct 16, 2026.
• Sales reported (open-market/private sales):
  • 7,539 shares at a reported weighted average price of $50.13 for $377,923 (footnote F2; range $50.00–$50.98).
  • 1,261 shares at a reported weighted average price of $51.53 for $64,980 (footnote F3; range $51.00–$51.90).
  • 2,000 shares at a reported weighted average price of $52.47 for $104,936 (footnote F4; range $52.02–$53.01).
  • 4,000 shares at a reported weighted average price of $53.44 for $213,745 (footnote F5; range $53.04–$53.91).
  • 200 shares at $54.27 for $10,854.
• Option exercise: 15,000 shares acquired at $8.12 per share for $121,800 (transaction report code M).
• Derivative disposition: 15,000 shares reported at $0.00 (transaction code M, listed as derivative).
• Relevant footnotes:
  • F1: Transactions occurred under a Rule 10b5-1 plan adopted Jun 5, 2026.
  • F2–F5: Reported sale prices are weighted averages; each footnote gives the range of individual trade prices and offers to provide breakdown on request.
  • F6: Vesting: 1/4 vested Feb 21, 2020, and 1/48 vested monthly thereafter, subject to continued service.
• Shares owned after the transaction: not reported in the provided excerpt.

Why it may matter

• The filing shows an exercise of 15,000 shares and sales of 15,000 shares on the same date, consistent with the shares being sold at once (cashless exercise).
• The sales were executed under a Rule 10b5-1 plan (F1) and several sales report weighted-average prices with price ranges (F2–F5).
• This filing does not show why the insider traded or why the company acted.