Ambiq Micro (AMBQ) President/COO Sean Chen Sells Shares, Exercises Options

What Happened
Sean Chen, President and COO of Ambiq Micro (AMBQ), reported exercising options to acquire 15,000 shares at $8.12 per share (cost $121,800) and selling 15,000 shares in open-market transactions on September 4, 2026 for total proceeds of approximately $857,558. The sales were split into two blocks (12,874 and 2,126 shares) at weighted-average prices shown below. The filing also records a separate derivative entry for 15,000 shares reported as disposed at $0 (see footnotes and Key Details).

Key Details

• Transaction date: September 4, 2026; Form 4 filed September 9, 2026.
• Option exercise (M): 15,000 shares acquired at $8.12; cash paid $121,800.
• Open-market sales (S): 12,874 shares at a weighted avg $57.09 (proceeds $734,933); 2,126 shares at a weighted avg $57.68 (proceeds $122,625). Total sale proceeds ≈ $857,558.
• Additional derivative line: 15,000 shares shown as disposed at $0 (reported as a derivative transaction).
• Shares owned after transaction: Not specified in the filing.
• Notable footnotes: F1 — sales occurred under a Rule 10b5-1 plan adopted June 5, 2026. F2/F3 — reported sale prices are weighted averages; actual execution prices ranged $56.54–$57.49 and $57.58–$57.79 for the two blocks. F4 — vesting schedule for the option grant is described (initial vesting in 2020, then monthly thereafter).
• Filing timeliness: filing date is Sept 9, 2026 (transaction Sept 4); the Form 4 shows those dates but the filing does not state any late-filing designation.

Context

• The reported option exercise is an acquisition of shares (a bullish action in isolation), but Chen concurrently sold the same number of shares in the open market. That pattern is consistent with exercising options and selling shares (including possible cashless/partial-sale mechanics), although the filing does not explain his intent.
• Sales were executed under a pre-arranged 10b5-1 plan (per F1), which is a routine mechanism insiders use to sell shares on a scheduled basis.
• All amounts and price ranges above are per the Form 4; the filer offers to provide per-trade price breakdowns on request (per F2/F3).