Thomas P. Gallagher - 15 Aug 2025 Form 4 Insider Report for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX)

Role
Chairman & CEO, Director
Signature
/s/Alessandra Maria Corona Henriques, Attorney-in-Fact
Issuer symbol
MIAX
Transactions as of
15 Aug 2025
Net transactions value
$0
Form type
4
Filing time
19 Aug 2025, 16:06:02 UTC
Previous filing
15 Aug 2025
Next filing
28 Aug 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Gallagher Thomas P. Chairman & CEO, Director C/O MIAMI INTERNATIONAL HOLDINGS, INC, 7 ROSZEL ROAD, SUITE 1A, PRINCETON /s/Alessandra Maria Corona Henriques, Attorney-in-Fact 19 Aug 2025 0002080477

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MIAX Common Stock Conversion of derivative security +500 +0.02% 2,040,494 15 Aug 2025 By Gallagher Investments, LLC F1, F2
transaction MIAX Common Stock Conversion of derivative security +573,963 +4783% 585,963 15 Aug 2025 Direct F3, F4
transaction MIAX Common Stock Conversion of derivative security +135,395 +7.1% 2,040,494 15 Aug 2025 By Gallagher Investments, LLC F2, F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction MIAX Series B Preferred Stock Conversion of derivative security $0 -500 -100% $0.000000 0 15 Aug 2025 Common Stock 500 By Gallagher Investments, LLC F1, F2
transaction MIAX Nonvoting Common Stock Conversion of derivative security $0 -573,963 -100% $0.000000 0 15 Aug 2025 Common Stock 573,963 Direct F3
transaction MIAX Nonvoting Common Stock Conversion of derivative security $0 -135,395 -100% $0.000000 0 15 Aug 2025 Common Stock 135,395 By Gallagher Investments, LLC F2, F5
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -24,999 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 24,999 $12.00 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +24,999 $0.000000 24,999 15 Aug 2025 Common Stock 24,999 $12.00 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -16,666 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 16,666 $12.00 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +16,666 $0.000000 16,666 15 Aug 2025 Common Stock 16,666 $12.00 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -8,333 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 8,333 $12.00 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +8,333 $0.000000 8,333 15 Aug 2025 Common Stock 8,333 $12.00 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -13,140 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 13,140 $15.22 Direct F6, F7
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +13,140 $0.000000 13,140 15 Aug 2025 Common Stock 13,140 $15.22 Direct F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -350,001 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 350,001 $12.00 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +350,001 $0.000000 350,001 15 Aug 2025 Common Stock 350,001 $12.00 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -283,334 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 283,334 $12.00 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +283,334 $0.000000 283,334 15 Aug 2025 Common Stock 283,334 $12.00 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -241,667 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 241,667 $12.00 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +241,667 $0.000000 241,667 15 Aug 2025 Common Stock 241,667 $12.00 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -286,860 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 286,860 $15.22 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +286,860 $0.000000 286,860 15 Aug 2025 Common Stock 286,860 $15.22 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -375,000 -100% $0.000000 0 15 Aug 2025 Nonvoting Common Stock 375,000 $16.14 By Gallagher Investments, LLC F2, F6, F7
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +375,000 $0.000000 375,000 15 Aug 2025 Common Stock 375,000 $16.14 By Gallagher Investments, LLC F2, F6, F7
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Represents 500 shares of Series B Preferred Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's initial public offering ("IPO") and which have no expiration date.
F2 Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC
F3 Represents 573,963 shares of Nonvoting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date.
F4 Includes 12,000 shares of common stock jointly with his spouse with right of survival
F5 Represents 135,395 shares of Nonvoting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date.
F6 The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions.
F7 The options are fully vested.