STOCK TITAN

MIAMI INTERNATIONAL (NASDAQ: MIAX) EVP exercises options, sells 28,000 shares under 10b5-1 plan

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

MIAMI INTERNATIONAL HOLDINGS, INC. executive Barbara J. Comly, EVP, General Counsel and Corporate Secretary, reported an exercise-and-sale transaction in company common stock. On 2026-06-02, she exercised nonqualified stock options for 28,000 shares at $12.00 per share and sold 28,000 shares in an open-market transaction at a weighted-average price of $42.85 per share. Following the sale, she directly held 843,844 common shares. The stock sale was carried out under a previously established Rule 10b5-1 trading plan adopted on December 18, 2025.

Positive

  • None.

Negative

  • None.
Insider Comly Barbara J.
Role EVP, GC & Corporate Secretary
Sold 28,000 shs ($1.20M)
Type Security Shares Price Value
Exercise Nonqualified Stock Option (Right to Buy) 28,000 $0.00 --
Exercise Common Stock 28,000 $12.00 $336K
Sale Common Stock 28,000 $42.85 $1.20M
Holdings After Transaction: Nonqualified Stock Option (Right to Buy) — 56,000 shares (Direct, null); Common Stock — 871,844 shares (Direct, null)
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 $41.31 to $45.73. The price reported above reflects the weighted average sales 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.
Shares sold 28,000 shares Open-market sale of common stock on June 2, 2026
Sale price (weighted average) $42.85 per share Weighted-average price for 28,000 shares sold
Exercise price $12.00 per share Nonqualified stock options exercised for 28,000 shares
Shares held after transaction 843,844 shares Direct MIAX common stock holdings after June 2, 2026
Options remaining 56,000 derivative securities Nonqualified stock options total following the exercise
Net share change -28,000 shares Net selling direction from transaction summary
Option expiration August 2, 2026 Expiration date of the nonqualified stock option grant
Rule 10b5-1 Plan regulatory
"This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 18, 2025."
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.
Nonqualified Stock Option financial
"Nonqualified Stock Option (Right to Buy)"
weighted average sales price financial
"The price reported above reflects the weighted average sales price."
open-market sale financial
"transaction_action: open-market sale"
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
derivative security financial
"transaction_code_description: Exercise or conversion of derivative security"
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.
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SEC Form 4
FORM 4UNITED 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)
Director10% Owner
XOfficer (give title below)Other (specify below)
EVP, GC & Corporate Secretary
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/02/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock06/02/2026M(1)28,000A$12871,844D
Common Stock06/02/2026S(1)28,000D$42.85(2)843,844D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Nonqualified Stock Option (Right to Buy)$1206/02/2026M(1)28,000 (3)08/02/2026Common Stock28,000$056,000D
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 $41.31 to $45.73. The price reported above reflects the weighted average sales 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-Fact06/04/2026
** Signature of Reporting PersonDate
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 insider transaction did MIAX executive Barbara J. Comly report?

Barbara J. Comly reported an exercise-and-sale in MIAX common stock. She exercised 28,000 nonqualified stock options at $12.00 per share and sold 28,000 shares in an open-market transaction at a weighted-average price of $42.85 per share.

How many MIAX shares did Barbara J. Comly sell and at what price?

She sold 28,000 MIAX common shares in the open market at a weighted-average price of $42.85 per share. The filing notes trades occurred throughout the day between $41.31 and $45.73, with the average price disclosed for reporting purposes.

How many MIAX shares does Barbara J. Comly hold after this Form 4 filing?

After the reported transactions, Barbara J. Comly directly holds 843,844 shares of MIAX common stock. This total reflects her position following the exercise of 28,000 options and the sale of 28,000 shares on June 2, 2026, as disclosed.

Were Barbara J. Comly’s MIAX stock sales under a Rule 10b5-1 plan?

Yes. The filing states the stock sale was effected under a previously established Rule 10b5-1 trading plan. That plan was adopted by Barbara J. Comly on December 18, 2025, indicating the transactions were pre-arranged rather than opportunistic.

What MIAX stock options did Barbara J. Comly exercise in this transaction?

She exercised 28,000 nonqualified stock options to acquire MIAX common shares at a conversion price of $12.00 per share. The derivative position is described as a nonqualified stock option with an expiration date of August 2, 2026, and the options are fully vested.

How many MIAX stock options remain after Barbara J. Comly’s exercise?

For the reported nonqualified stock option, the entry shows 56,000 derivative securities remaining after the exercise. This figure is listed as the total derivative shares following the transaction, giving context to the size of the exercised portion relative to that option grant.