MIAMI INTERNATIONAL HOLDINGS, INC.·4

May 7, 4:07 PM ET

Gallagher Thomas P. 4

4 · MIAMI INTERNATIONAL HOLDINGS, INC. · Filed May 7, 2026

Research Summary

AI-generated summary of this filing

Updated

MIAX CEO Thomas Gallagher Sells 15,771 Shares After Exercising Options

What Happened

  • Thomas P. Gallagher, Chairman & CEO of Miami International Holdings, exercised 15,771 stock options (fully vested) at a $12.00 exercise price (cost $189,252) on May 5, 2026 and sold the 15,771 shares the same day in open-market trades for total proceeds of $755,746. The exercise and immediate sale produced a gross spread of roughly $566,494 before fees and taxes.
  • The sale was executed under a previously established Rule 10b5-1 trading plan adopted December 29, 2025.

Key Details

  • Transaction date: May 5, 2026; Form filed May 7, 2026 (timely filing).
  • Exercise: 15,771 shares @ $12.00 = $189,252 (acquired).
  • Sale: 15,771 shares @ weighted average $47.92 = $755,746 (disposed). Reported trade prices ranged $47.13–$48.35 (multiple trades).
  • A related derivative line shows the option conversion/disposition as $0, reflecting the options were exercised/terminated.
  • Options were fully vested. Reporting person retains beneficial ownership/control via Gallagher Investments, LLC (per filing).
  • Shares owned after the transaction are not specified in the Form 4.

Context

  • This is effectively a cashless exercise: the insider exercised options and immediately sold the acquired shares the same day to realize proceeds. Such transactions are often for liquidity (taxes/financing) and are commonly executed under 10b5-1 plans; they do not by themselves indicate a change in insider sentiment.
  • The filing discloses the 10b5-1 plan and provides a weighted-average sale price; the filer offered to supply detailed per-trade prices on request.

Insider Transaction Report

Form 4
Period: 2026-05-05
Gallagher Thomas P.
DirectorChairman & CEO
Transactions
  • Exercise/Conversion

    Common Stock

    [F1][F2]
    2026-05-05$12.00/sh+15,771$189,2521,739,046 total(indirect: By LLC)
  • Sale

    Common Stock

    [F1][F3][F2]
    2026-05-05$47.92/sh15,771$755,7461,723,275 total(indirect: By LLC)
  • Exercise/Conversion

    Nonqualified Stock Option (Right to Buy)

    [F1][F4][F2]
    2026-05-0515,771210,000 total(indirect: By LLC)
    Exercise: $12.00Exp: 2026-08-02Common Stock (15,771 underlying)
Footnotes (4)
  • [F1]This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025.
  • [F2]Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC.
  • [F3]This transaction was executed in multiple trades throughout the day at prices ranging from $47.13 to $48.35. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
  • [F4]The options are fully vested.
Signature
/s/Alessandra Maria Corona Henriques, Attorney-in-Fact|2026-05-07

Documents

1 file
  • 4
    wk-form4_1778184416.xmlPrimary

    FORM 4