Barbara J. Comly - Aug 15, 2025 Form 4 Insider Report for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX)

Role
EVP, GC & Corporate Secretary
Signature
/s/Alessandra Maria Corona Henriques, Attorney-in-Fact
Stock symbol
MIAX
Transactions as of
Aug 15, 2025
Transactions value $
$0
Form type
4
Date filed
8/19/2025, 04:06 PM
Previous filing
Aug 13, 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Comly Barbara J. EVP, GC & Corporate Secretary C/O MIAMI INTERNATIONAL HOLDINGS, INC., 7 ROSZEL ROAD, SUITE 1A, PRINCETON /s/Alessandra Maria Corona Henriques, Attorney-in-Fact 2025-08-19 0002080878

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MIAX Common Stock Conversion of derivative security +101K +14.13% 812K Aug 15, 2025 Direct F1
transaction MIAX Common Stock Conversion of derivative security +131K +19.17% 812K Aug 15, 2025 Direct F2

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 -101K -100% $0.00 0 Aug 15, 2025 Common Stock 101K Direct F1
transaction MIAX Nonvoting Common Stock Conversion of derivative security $0 -131K -100% $0.00 0 Aug 15, 2025 Common Stock 131K Direct F2
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -8.33K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 8.33K $12.00 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +8.33K $0.00 8.33K Aug 15, 2025 Common Stock 8.33K $12.00 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -16.7K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 16.7K $12.00 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +16.7K $0.00 16.7K Aug 15, 2025 Common Stock 16.7K $12.00 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -8.33K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 8.33K $12.00 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +8.33K $0.00 8.33K Aug 15, 2025 Common Stock 8.33K $12.00 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 -13.1K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 13.1K $15.22 Direct F3, F4
transaction MIAX Incentive Stock Option (Right to Buy) Options Exercise $0 +13.1K $0.00 13.1K Aug 15, 2025 Common Stock 13.1K $15.22 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -142K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 142K $12.00 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +142K $0.00 142K Aug 15, 2025 Common Stock 142K $12.00 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -133K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 133K $12.00 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +133K $0.00 133K Aug 15, 2025 Common Stock 133K $12.00 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -142K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 142K $12.00 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +142K $0.00 142K Aug 15, 2025 Common Stock 142K $12.00 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -137K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 137K $15.22 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +137K $0.00 137K Aug 15, 2025 Common Stock 137K $15.22 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 -150K -100% $0.00 0 Aug 15, 2025 Nonvoting Common Stock 150K $16.14 Direct F3, F4
transaction MIAX Nonqualified Stock Option (Right to Buy) Options Exercise $0 +150K $0.00 150K Aug 15, 2025 Common Stock 150K $16.14 Direct F3, F4
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Represents 100,500 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 Represents 130,617 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.
F3 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.
F4 The options are fully vested.