MIAX CEO Thomas P. Gallagher Exercises Options, Sells Shares

What Happened
Thomas P. Gallagher, Chairman, CEO and Director of Miami International Holdings, Inc. (MIAX), exercised a total of 70,000 stock options (fully vested) at a $12.00 strike and immediately sold the resulting 70,000 shares in open-market transactions. He exercised 41,772 options on 2026-07-06 (cost $501,264) and sold those shares for a weighted average price of $42.09 (proceeds $1,758,183). He exercised the remaining 28,228 options on 2026-07-07 (cost $338,736) and sold those shares for a weighted average price of $42.27 (proceeds $1,193,198). Total exercise cost = $840,000; total gross sale proceeds ≈ $2,951,381.

Key Details

• Transaction dates: 2026-07-06 (41,772 shares) and 2026-07-07 (28,228 shares).
• Exercise price: $12.00 per share; sale weighted average prices: $42.09 (7/6, range $42.00–$42.32) and $42.27 (7/7, range $42.00–$42.50).
• Total exercised: 70,000 options; total sold: 70,000 shares.
• Total exercise cost: $840,000; total reported sale proceeds: ≈ $2,951,381.
• Footnotes: one of the transactions was effected under a previously established Rule 10b5-1 trading plan (adopted 12/29/2025). The sales were executed in multiple trades (weighted-average prices reported). The options were fully vested. Mr. Gallagher retains beneficial ownership/control of Gallagher Investments, LLC.
• Shares owned after transaction: not specified in the provided filing excerpt.
• Filing timeliness: Form 4 was filed 2026-07-07 for transactions dated 2026-07-06–07; this appears to be timely (not marked late).

Context

• This sequence is a common pattern: exercising vested options and immediately selling the shares (effectively realizing the spread between market price and strike). The derivative "disposals" at $0 reported reflect the conversion of option instruments into common shares upon exercise.
• The presence of a 10b5-1 plan for at least one sale indicates at least part of the selling was preplanned, which is routine for company insiders managing tax or diversification events.
• Facts only — this summary does not infer Mr. Gallagher’s motivations beyond what the filing states.