David A. Brown - Aug 13, 2025 Form 3 Insider Report for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX)

Role
Director
Signature
/s/Alessandra Maria Corona Henriques, Attorney-in-Fact
Stock symbol
MIAX
Transactions as of
Aug 13, 2025
Transactions value $
$0
Form type
3
Date filed
8/13/2025, 05:09 PM
Previous filing
May 19, 2025
Next filing
Aug 19, 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
BROWN DAVID A Director C/O MIAMI INTERNATIONAL HOLDINGS, INC., 7 ROSZEL ROAD, SUITE 1A, PRINCETON /s/Alessandra Maria Corona Henriques, Attorney-in-Fact 2025-08-13 0001394399

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
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Nonvoting Common Stock 18.8K $16.14 Direct F1
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Nonvoting Common Stock 7.5K $16.14 Direct F1
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Nonvoting Common Stock 278 $16.14 Direct F1
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Common Stock 11K $25.98 Direct F2
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Common Stock 11.7K $19.84 Direct F2
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Common Stock 9.17K $20.00 Direct F2
holding MIAX Stock Option (Right to Buy) Aug 13, 2025 Common Stock 8.31K $22.34 Direct F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 The options are fully vested. The options were granted initially as the right to buy nonvoting common stock. On the closing date of the Company's initial public offering of its common stock (the "IPO"), these will convert to the right to buy common stock instead of nonvoting common stock.
F2 The options are fully vested.
F3 4,153 of the shares subject to this option vested on June 30, 2025, 2,076 of the shares subject to this option will vest on September 30, 2025 and the remaining 2,076 will vest on December 31, 2025, subject to the reporting person's continued service to the Issuer or its subsidiaries through the applicable vesting date.

Remarks:

See Exhibit 24.1 - Power of Attorney