SEC Form 4 · accession 0002080477-26-000018
MIAMI INTERNATIONAL HOLDINGS, INC. · MIAX
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
Thomas P. Gallagher
Officer — Chairman & CEO · Director
Period of report
Sep 3, 2026
Accepted (ET)
Sep 4, 2026 · 4:35 pm EDT
Rule 10b5-1 plan
yes — trade under a plan
Issuer CIK
0001438472
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Common StockF2 | Sep 3, 2026 | M | 47,000 | $12.00 | A | 1,470,275 | I | By Gallagher Investments, LLC |
| Common StockF3,F2 | Sep 3, 2026 | S | 47,000 | $42.43 | D | 1,423,275 | I | By Gallagher Investments, LLC |
| Common Stock | Sep 3, 2026 | M | 16,666 | $12.00 | A | 760,605 | D | |
| Common Stock | Sep 3, 2026 | M | 8,333 | $12.00 | A | 768,938 | D | |
| Common Stock | Sep 3, 2026 | M | 13,140 | $15.22 | A | 782,078 | D | |
| Common Stock | Sep 3, 2026 | M | 4,464 | $22.40 | A | 786,542 | D |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Nonqualified Stock Option (Right to Buy)F2,F4 | $12.00 | Sep 3, 2026 | M | 47,000 | D | — | May 28, 2028 | Common Stock | 47,000 | 188,000 | I |
| Incentive Stock Option (Right to Buy)F4 | $12.00 | Sep 3, 2026 | M | 16,666 | D | — | May 28, 2028 | Common Stock | 16,666 | 0 | D |
| Incentive Stock Option (Right to Buy)F4 | $12.00 | Sep 3, 2026 | M | 8,333 | D | — | Jul 30, 2029 | Common Stock | 8,333 | 0 | D |
| Incentive Stock Option (Right to Buy)F4 | $15.22 | Sep 3, 2026 | M | 13,140 | D | — | Jan 27, 2031 | Common Stock | 13,140 | 0 | D |
| Incentive Stock Option (Right to Buy)F5 | $22.40 | Sep 3, 2026 | M | 4,464 | D | — | Jun 15, 2035 | Common Stock | 4,464 | 8,928 | D |
Explanation of responses
- F1This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025.
- F2Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC.
- F3This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $42.68. The price reported above reflects the weighted average sales 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.
- F4The options are fully vested.
- F54,464 of the shares subject to this incentive stock option are vested. 4,464 shares subject to this incentive stock option will vest on June 16, 2027 and the remaining 4,464 shares subject to this incentive stock option will vest on June 16, 2028, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date.