Director Teekell exercises MIAX (NASDAQ: MIAX) options and ends with 79,005 shares

Rhea-AI Filing Summary

MIAMI INTERNATIONAL HOLDINGS director Judson Gray Teekell exercised stock options and had shares withheld for taxes. On May 19, 2026, he exercised options to acquire 22,667 shares of common stock at an exercise price of $12.00 per share.

The company withheld 4,991 shares at a reference price of $54.51 per share to cover the option exercise price and related tax obligations, which the footnote states does not represent a market sale. Following these transactions, Teekell directly holds 79,005 common shares.

Insider Trade Summary

22,667 shares exercised/converted

Mixed 3 txns

Insider Teekell Judson Gray

Role null

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy)	22,667	$0.00	--
Exercise	Common Stock	22,667	$12.00	$272K
Tax Withholding	Common Stock	4,991	$54.51	$272K

Holdings After Transaction: Stock Option (Right to Buy) — 0 shares (Direct, null); Common Stock — 79,005 shares (Direct, null)

Footnotes (1)

1. Represents shares that have been withheld by the Issuer to cover the exercise price of the options exercised and does not represent a sale by the Reporting Person. The options are fully vested.

Key Figures

Options exercised: 22,667 shares Exercise price: $12.00 per share Shares withheld for taxes: 4,991 shares +4 more

7 metrics

Options exercised 22,667 shares Common Stock acquired via option exercise on May 19, 2026

Exercise price $12.00 per share Stock Option (Right to Buy) conversion price

Shares withheld for taxes 4,991 shares Withheld by issuer at $54.51 to cover exercise price and taxes

Withholding reference price $54.51 per share Price used for tax and exercise-coverage withholding

Shares owned after transactions 79,005 shares Direct MIAX common stock holding following Form 4 events

Option expiration date June 19, 2026 Expiration of exercised Stock Option (Right to Buy)

Transaction date May 19, 2026 Date of option exercise and tax-withholding disposition

Key Terms

Stock Option (Right to Buy), tax-withholding disposition, Exercise or conversion of derivative security, exercise price, +1 more

5 terms

Stock Option (Right to Buy) financial

"Security title listed as Stock Option (Right to Buy) with 22,667 shares"

tax-withholding disposition financial

"Transaction action described as tax-withholding disposition under code F"

A tax-withholding disposition is an event or transaction—such as selling or transferring securities, exercising options, or receiving compensation—that triggers a requirement to hold back part of the payment and remit it to tax authorities. It matters to investors because it reduces the cash they receive immediately and can change the timing and amount of taxable income, like a cashier taking a portion of your sale proceeds to pay taxes before you get the rest.

Exercise or conversion of derivative security financial

"Transaction code M defined as Exercise or conversion of derivative security"

exercise price financial

"Footnote notes shares withheld to cover the exercise price of options exercised"

The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.

derivative security financial

"M code transaction relates to a derivative security converted into common stock"

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Teekell Judson Gray

(Last) (First) (Middle)

C/O MIAMI INTERNATIONAL HOLDINGS, INC.

7 ROSZEL ROAD, SUITE 1A

(Street)

PRINCETON NEW JERSEY 08540

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
MIAMI INTERNATIONAL HOLDINGS, INC. [ MIAX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/19/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/19/2026		M		22,667	A	$12	79,005	D
Common Stock	05/19/2026		F		4,991(1)	D	$54.51	74,014	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$12	05/19/2026		M			22,667	(2)	06/19/2026	Common Stock	22,667	$0	0	D

Explanation of Responses:

1. Represents shares that have been withheld by the Issuer to cover the exercise price of the options exercised and does not represent a sale by the Reporting Person.

2. The options are fully vested.

Remarks:

	/s/ Barbara J. Comly, Attorney-in-Fact	05/19/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What did MIAX director Judson Gray Teekell report in this Form 4?

Judson Gray Teekell reported exercising stock options and having shares withheld for taxes. He acquired 22,667 MIAX common shares through option exercise and had 4,991 shares withheld, ending with 79,005 shares directly owned.

Did Judson Gray Teekell sell MIAX shares in this Form 4 transaction?

He did not report an open-market sale. The Form 4 shows 4,991 shares withheld by the issuer at $54.51 per share to cover the option exercise price and tax obligations, with the footnote specifying this does not represent a sale.

How many MIAX shares did Teekell acquire through option exercise?

Teekell exercised stock options covering 22,667 MIAX common shares. These options had a stated exercise price of $12.00 per share, converting a derivative position into additional directly held common stock as part of his equity compensation.

What is Judson Gray Teekell’s MIAX shareholding after these transactions?

After the reported transactions, Teekell directly owns 79,005 MIAX common shares. This figure reflects the net result of exercising 22,667 options and the withholding of 4,991 shares to satisfy the option exercise price and taxes.

What were the key prices in Teekell’s MIAX Form 4 transactions?

The options were exercised at $12.00 per share, while 4,991 shares were withheld at a reference price of $54.51 per share. These prices define the cost of exercising the options and the value used for tax and exercise-coverage withholding.

When do the exercised MIAX stock options expire according to the Form 4?

The exercised stock options had an expiration date of June 19, 2026. Exercising them on May 19, 2026 converted the derivative award into 22,667 common shares before the stated expiration of the option grant.