Miami International (MIAX) EVP sells 48K shares after exercising options

Rhea-AI Filing Summary

MIAMI INTERNATIONAL HOLDINGS, INC. executive Douglas M. Schafer Jr., EVP and CIO, executed an option exercise-and-sale on Common Stock. On June 2, 2026, he exercised 48,000 Nonqualified Stock Options at $12.00 per share to acquire 48,000 common shares, then sold those 48,000 shares in an open-market transaction at a weighted average price of $42.84 per share. These trades were carried out under a previously established Rule 10b5-1 Plan adopted on December 16, 2025. After the transactions, he directly holds 396,681 common shares and 6,000 Nonqualified Stock Options, which are fully vested and remain exercisable until their stated expiration.

Insights

Equity Compensation Analyst

Routine option exercise-and-sale under a 10b5-1 plan with stable share holdings.

EVP and CIO Douglas M. Schafer Jr. exercised 48,000 Nonqualified Stock Options at a strike price of $12.00, then sold the same 48,000 common shares at a weighted average of $42.84. This pattern is a classic exercise-and-sell sequence, monetizing option value while leaving his common share count unchanged at 396,681 shares.

The filing notes the options are fully vested and that the sale was executed pursuant to a previously established Rule 10b5-1 Plan adopted on December 16, 2025. Such plans pre-schedule trades, suggesting the timing reflects a preset strategy rather than a discretionary market call.

Following the exercise, he retains 6,000 Nonqualified Stock Options, with an expiration date of August 2, 2026, alongside his direct holdings of 396,681 common shares. Subsequent filings may provide further detail if additional options are exercised as the remaining options approach expiration.

Insider Trade Summary 10b5-1

Net Seller: 48,000 shares ($2,056,320)

Net Sell 3 txns

Insider Schafer Douglas M. JR

Role EVP and CIO

Sold 48,000 shs ($2.06M)

Type	Security	Shares	Price	Value
Exercise	Nonqualified Stock Option (Right to Buy)	48,000	$0.00	--
Exercise	Common Stock	48,000	$12.00	$576K
Sale	Common Stock	48,000	$42.84	$2.06M

Holdings After Transaction: Nonqualified Stock Option (Right to Buy) — 6,000 shares (Direct, null); Common Stock — 444,681 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 16, 2025. This transaction was executed in multiple trades throughout the day at prices ranging from $41.23 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.

Key Figures

Shares sold: 48,000 shares Sale price: $42.84 per share Option strike price: $12.00 per share +5 more

8 metrics

Shares sold 48,000 shares Common Stock sold in open-market transaction on June 2, 2026

Sale price $42.84 per share Weighted average sales price for 48,000 common shares

Option strike price $12.00 per share Nonqualified Stock Option exercise price for 48,000 shares

Shares after transaction 396,681 shares Direct MIAX common shares held following June 2, 2026 trades

Options exercised 48,000 options Nonqualified Stock Options converted into common shares

Options remaining 6,000 options Nonqualified Stock Options outstanding after exercise, fully vested

Option expiration August 2, 2026 Expiration date of Nonqualified Stock Options position

10b5-1 plan adoption December 16, 2025 Date Rule 10b5-1 trading plan was adopted

Key Terms

Rule 10b5-1 Plan, Nonqualified Stock Option, weighted average sales price, fully vested, +1 more

5 terms

Rule 10b5-1 Plan regulatory

"This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person"

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

"security_title: "Nonqualified Stock Option (Right to Buy)" with an exercise price of $12.0000"

weighted average sales price financial

"The price reported above reflects the weighted average sales price."

fully vested financial

"The options are fully vested."

open-market sale financial

"transaction_action: "open-market sale" for 48,000 shares of Common Stock"

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.

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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^*

Schafer Douglas M. JR

(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 and CIO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/02/2026

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	06/02/2026		M(1)		48,000	A	$12	444,681	D
Common Stock	06/02/2026		S(1)		48,000	D	$42.84(2)	396,681	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	06/02/2026		M(1)			48,000	(3)	08/02/2026	Common Stock	48,000	$0	6,000	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 16, 2025.

2. This transaction was executed in multiple trades throughout the day at prices ranging from $41.23 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 Henriques Corona, Attorney-in-fact	06/04/2026
	** 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 insider transactions did MIAX executive Douglas Schafer report on June 2, 2026?

Douglas M. Schafer Jr. reported exercising 48,000 Nonqualified Stock Options at $12.00 and selling 48,000 MIAX common shares at a weighted average price of $42.84. This created cash from options while keeping his direct common share count unchanged at 396,681 shares.

How many MIAX (MIAX) shares does Douglas Schafer hold after this Form 4 filing?

After the reported transactions, Douglas M. Schafer Jr. directly holds 396,681 MIAX common shares. He also retains 6,000 fully vested Nonqualified Stock Options, which remain exercisable until their stated expiration date, providing additional potential equity exposure beyond his current share ownership.

Were Douglas Schafer’s MIAX stock sales made under a Rule 10b5-1 plan?

Yes. The filing states the June 2, 2026 MIAX stock sale was effected under a previously established Rule 10b5-1 Plan adopted on December 16, 2025. Such plans pre-arrange trades, indicating the timing followed a preset schedule rather than a new discretionary decision.

What prices were involved in Douglas Schafer’s MIAX option exercise and share sale?

Douglas M. Schafer Jr. exercised 48,000 MIAX Nonqualified Stock Options at a strike price of $12.00 per share, then sold 48,000 common shares at a weighted average price of $42.84. Actual sale trades occurred between $41.23 and $45.73 during the day.

Did Douglas Schafer reduce his MIAX common share holdings in this Form 4?

His direct MIAX common share count remained at 396,681 shares. He acquired 48,000 shares through an option exercise and sold the same 48,000 shares in the open market. The net change is a reduction in option holdings, not in his direct share position.

What happens to Douglas Schafer’s remaining MIAX Nonqualified Stock Options?

After exercising 48,000 options, Douglas M. Schafer Jr. retains 6,000 fully vested Nonqualified Stock Options linked to MIAX common stock. These remaining options are exercisable until their stated expiration date of August 2, 2026, subject to standard plan and agreement terms.