MIAX (MIAX) EVP Comly exercises options, sells 29,667 shares under 10b5-1 plan

Rhea-AI Filing Summary

MIAMI INTERNATIONAL HOLDINGS, INC. EVP, GC & Corporate Secretary Barbara J. Comly exercised options and sold shares in a planned transaction. She exercised nonqualified stock options for 29,667 shares of common stock at $12.00 per share and sold 29,667 shares at a weighted average price of $43.64 per share under a previously established Rule 10b5-1 Plan. Following these transactions, she directly holds 843,844 shares of common stock. The exercised options were fully vested, and the sale price reflects trades executed between $42.68 and $44.37 on the same date.

Insider Trade Summary 10b5-1

Net Seller: 29,667 shares ($1,294,668)

Net Sell 3 txns

Insider Comly Barbara J.

Role EVP, GC & Corporate Secretary

Sold 29,667 shs ($1.29M)

Type	Security	Shares	Price	Value
Exercise	Nonqualified Stock Option (Right to Buy)	29,667	$0.00	--
Exercise	Common Stock	29,667	$12.00	$356K
Sale	Common Stock	29,667	$43.64	$1.29M

Holdings After Transaction: Nonqualified Stock Option (Right to Buy) — 112,000 shares (Direct); Common Stock — 873,511 shares (Direct)

Footnotes (1)

1. This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the reporting person on December 18, 2025. This transaction was executed in multiple trades throughout the day at prices ranging from $42.68 to $44.37. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. The options are fully vested.

Key Figures

Options exercised: 29,667 shares Option exercise price: $12.00 per share Shares sold: 29,667 shares +3 more

6 metrics

Options exercised 29,667 shares Nonqualified Stock Option for common stock exercised on April 15, 2026

Option exercise price $12.00 per share Exercise price for 29,667 nonqualified stock options

Shares sold 29,667 shares Open-market sale of common stock on April 15, 2026

Weighted average sale price $43.64 per share Common stock sales executed between $42.68 and $44.37

Post-transaction holdings 843,844 shares Common stock directly owned after the sale

Sale price range $42.68–$44.37 per share Intraday price range for the 29,667 shares sold

Key Terms

Nonqualified Stock Option, Rule 10b5-1 Plan, weighted average sale price, fully vested

4 terms

Nonqualified Stock Option financial

"Nonqualified Stock Option (Right to Buy) covering 29,667 shares"

Rule 10b5-1 Plan regulatory

"transaction was effected pursuant to a previously established Rule 10b5-1 Plan"

A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.

weighted average sale price financial

"price reported above reflects the weighted average sale price"

fully vested financial

"The options are fully vested."

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).

X

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^*

Comly Barbara J.

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, GC & Corporate Secretary

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/15/2026

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	04/15/2026		M(1)		29,667	A	$12	873,511	D
Common Stock	04/15/2026		S(1)		29,667	D	$43.64(2)	843,844	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
Nonqualified Stock Option (Right to Buy)	$12	04/15/2026		M(1)			29,667	(3)	08/02/2026	Common Stock	29,667	$0	112,000	D

Explanation of Responses:

1. This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the reporting person on December 18, 2025.

2. This transaction was executed in multiple trades throughout the day at prices ranging from $42.68 to $44.37. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

3. The options are fully vested.

Remarks:

	/s/Alessandra Maria Corona Henriques, Attorney-in-Fact	04/17/2026
	** 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 executive Barbara J. Comly do in this Form 4 filing?

Barbara J. Comly exercised options for 29,667 MIAX shares at $12.00 and sold 29,667 shares at a weighted average price of $43.64. The transactions reflect an exercise-and-sell pattern, converting a derivative position into cash while retaining a substantial remaining shareholding.

How many MIAX shares does Barbara J. Comly hold after these transactions?

After the reported transactions, Barbara J. Comly directly holds 843,844 shares of MIAX common stock. This figure comes after exercising 29,667 options and selling 29,667 shares, indicating she maintains a significant equity position in the company despite the same-day sale.

At what prices were Barbara J. Comly’s MIAX transactions executed?

She exercised options at an exercise price of $12.00 per share and sold 29,667 MIAX shares at a weighted average price of $43.64. The sale occurred through multiple trades during the day, with prices ranging from $42.68 to $44.37 per share.

Was Barbara J. Comly’s MIAX share sale part of a pre-planned trading program?

Yes. The sale of 29,667 MIAX shares was executed under a previously established Rule 10b5-1 Plan adopted on December 18, 2025. Such plans are pre-arranged trading programs that schedule transactions in advance, helping separate trading activity from short-term market information.

What type of securities did Barbara J. Comly exercise in this MIAX Form 4?

She exercised a Nonqualified Stock Option covering 29,667 underlying MIAX common shares at an exercise price of $12.00 per share. The filing notes that these options were fully vested, meaning all 29,667 option shares were already earned and eligible for exercise on the transaction date.

How many MIAX options did Barbara J. Comly have remaining after this transaction?

The filing’s derivative summary shows no remaining derivative positions for Barbara J. Comly after this exercise. This indicates that the 29,667 fully vested nonqualified stock options reported in the transaction were completely exercised, leaving no additional options disclosed in this particular report.