MIAMI INTERNATIONAL HOLDINGS, INC.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

(Amendment No. )

Notice of Annual Meeting of Stockholders

and Proxy Statement

MESSAGE FROM THE CHAIRMAN OF THE BOARD

April 27, 2026

Dear MIAX Stockholder:

We cordially invite you to attend the 2026 Annual Meeting of Stockholders (the “Annual

Meeting”) of Miami International Holdings, Inc. to be held on Tuesday, June 16, 2026, at 8:00

a.m., Eastern Time, via live webinar.

The Annual Meeting will be a completely virtual meeting of stockholders and there will

be no physical meeting location. You will be able to attend the Annual Meeting, vote your shares

and submit questions during the meeting via live audio webcast by visiting

www. virtualshareholdermeeting.com/MIAX2026 and entering the 16-digit control number

included in your proxy materials or on your proxy card. The live audio webcast of the Annual

Meeting will also be available for listening by the general public. For further information on the

Annual Meeting logistics, see the section titled “Questions and Answers About the Proxy

Materials and our Annual Meeting.”

At the Annual Meeting, you will be asked to do the following:

1. Elect 15 directors to our board of directors to hold office until the 2027 annual

meeting of stockholders or until their respective successors have been elected and

qualified, or until such director’s earlier death, resignation, or removal;

2. Approve, on a non-binding advisory basis, the compensation paid to our named

3. Select, on a non-binding advisory basis, whether future advisory votes on the

compensation of our named executive officers should be held every one, two, or

three years;

4. Ratify the appointment of KPMG LLP as our independent registered public

accounting firm for the year ending December 31, 2026; and

5. Transact any other business that may properly come before the meeting and any

adjournments and postponements of the meeting.

Enclosed with this letter are the following: a formal notice of the Annual Meeting, a

proxy statement, and a form of proxy.

Please carefully review the form of proxy that you receive to confirm that it reflects all

of your shares of our common stock. If you hold common stock in different accounts, you may

need to complete multiple proxy cards to vote all of your shares.

Whether or not you plan to attend the Annual Meeting via live audio webcast, it is

important that your shares be represented and voted. Please submit your proxy by internet,

telephone, or complete, sign, date and return the enclosed proxy card using the enclosed postage-

paid envelope. The enclosed proxy card, when returned properly executed, will be voted in the

manner directed in the proxy.

We hope that you will participate in the Annual Meeting, either via live audio webcast or

by proxy.

Sincerely,

Thomas P. Gallagher

Chairman and Chief Executive Officer

MIAMI INTERNATIONAL HOLDINGS, INC.

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

The 2026 Annual Meeting of Stockholders (the “Annual Meeting”) of Miami

International Holdings, Inc. (the “Company”) will be held on Tuesday, June 16, 2026, at 8:00

a.m., Eastern Time, via live webinar.

The Annual Meeting will be a completely virtual meeting of stockholders. You will be

able to attend the Annual Meeting, vote your shares and submit questions during the meeting via

live audio webcast by visiting www. virtualshareholdermeeting.com/MIAX2026 and entering the

16-digit control number included in your proxy materials or on your proxy card. Online check-in

to the Annual Meeting live audio webcast will begin at 7:45 a.m., Eastern Time, and you are

encouraged to allow ample time to log in to the meeting webcast and test your computer audio

system. There will be no physical meeting location. For further information on Annual Meeting

logistics, see the section titled “Questions and Answers About the Proxy Materials and our

Annual Meeting.”

The purpose of the Annual Meeting is to:

1. Consider and act upon the election of 15 directors named in the proxy statement

(the “Proxy Statement”) to the Board of Directors of the Company (the “Board”)

to hold office until the 2027 Annual Meeting of Stockholders (the “2027 Annual

Meeting”) or until their respective successors have been elected and qualified, or

until such director’s earlier death, resignation or removal;

2. Consider and approve, on a non-binding advisory basis, the compensation paid to

our named executive officers;

3. Select, on a non-binding advisory basis, whether future advisory votes on the

compensation of our named executive officers should be held every one, two, or

three years;

4. Consider and act upon the ratification of the appointment of KPMG LLP

(“KPMG”) as our independent registered public accounting firm for the year

ending December 31, 2026; and

5. Transact any other business that may properly come before the meeting and any

adjournments or postponements of the meeting.

You are entitled to vote online during the Annual Meeting and any adjournments or

postponements of the meeting if you were a stockholder of record at the close of business on

April 20, 2026. A list of stockholders of record will be open for examination by any stockholder

for any purpose germane to the Annual Meeting during ordinary business hours for a period of

ten days prior to the Annual Meeting at our principal executive offices at 7 Roszel Road, Suite

1A, Princeton, NJ 08540. The approximate date on which the Proxy Statement and the

accompanying form of proxy are first being sent to stockholders is April 27, 2026.

Your vote is important. Whether or not you plan to attend the Annual Meeting,

please vote as soon as possible. For additional details, please see the information under

“How do I vote?” in the Proxy Statement.

By Order of the Board of Directors,

Barbara J. Comly

Executive Vice President, General Counsel and Corporate Secretary

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS

FOR THE STOCKHOLDER MEETING TO BE HELD ON JUNE 16, 2026:

This notice of Annual Meeting and Proxy Statement and our annual report on Form 10-K

for the year ended December 31, 2025 (the“Annual Report on Form 10-K”) are available free of

charge on our investor relations website at http://ir.miaxglobal.com under the tab“SEC Filings”.

We are furnishing the Proxy Statement to you in connection with a solicitation of proxies by the

Board, for use at the Annual Meeting on Tuesday, June 16, 2026 at 8:00 a.m. Eastern Time, and

at any adjournments or postponements thereof.

TABLE OFCONTENTS

Except as otherwise indicated, the terms “MIAX,” the “Company,” “we,” “us” and “our”

refer to Miami International Holdings, Inc., together with its wholly-owned subsidiaries. The

term “MIAX Exchanges” refers, collectively, to our Securities and Exchange Commission (the

“SEC”) regulated exchanges, each a “MIAX Exchange”: Miami International Securities

Exchange, LLC (“MIAX Options”), MIAX Pearl, LLC (“MIAX Pearl”), the equities trading

facility of MIAX Pearl (“MIAX Pearl Equities”), MIAX Emerald, LLC (“MIAX Emerald”) and

MIAX Sapphire, LLC (“MIAX Sapphire”).

MIAX®, MIAX Options®, MIAX Pearl®, MIAX Emerald® and MIAX Sapphire® are

registered trademarks or service marks in the United States and certain other jurisdictions of

MIAX. MIAX Futures™ and TINI™ are currently pending.

This Proxy Statement contains references to our trademarks and service marks and to

those belonging to other entities. Solely for convenience, trademarks and trade names referred to

herein, including logos, artwork, and other visual displays, may appear without the® or™

symbols, but in the case of our trademarks and trade names or those of our licensors, such

references are not intended to indicate in any way that we will not assert, to the fullest extent

under applicable law, our rights or the rights of the applicable licensor to these trademarks and

trade names. We do not intend our use or display of other entities’ trade names, trademarks, or

service marks to imply a relationship with, or endorsement or sponsorship of us by, any other

entity.

SPECIAL NOT