MIAMI INTERNATIONAL (MIAX) EVP Shelly Brown trims stake with 3,257-share sale

Filing Impact

(Moderate)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

MIAMI INTERNATIONAL HOLDINGS, INC. executive Shelly Brown, EVP and Chief Strategy Officer, sold a total of 3,257 shares of common stock in two open-market transactions. On April 7, 2026, she sold 900 shares at about $42.00 per share. On April 6, 2026, she sold 2,357 shares at about $41.33 per share. After these sales, she directly holds 324,147 shares. The filing notes that at least one transaction was carried out under a pre-established Rule 10b5-1 trading plan, indicating the sales were pre-planned rather than timed discretionarily.

Insider Trade Summary 10b5-1

Net Seller: 3,257 shares ($135,215)

Net Sell 2 txns

Insider Brown Shelly

Role EVP, Chief Strategy Officer

Sold 3,257 shs ($135K)

Type	Security	Shares	Price	Value
Sale	Common Stock	900	$42.00	$38K
Sale	Common Stock	2,357	$41.33	$97K

Holdings After Transaction: Common Stock — 324,147 shares (Direct)

Footnotes (1)

This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the reporting person on December 22, 2025. This transaction was executed in multiple trades throughout the day at prices ranging from $40.10 to $41.79. 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.

Key Figures

Shares sold: 3,257 shares Sale price 7 Apr 2026: $42.00 per share Sale price 6 Apr 2026: $41.33 per share +2 more

5 metrics

Shares sold 3,257 shares Total common stock sold in two transactions

Sale price 7 Apr 2026 $42.00 per share 900-share open-market sale of common stock

Sale price 6 Apr 2026 $41.33 per share 2,357-share open-market sale of common stock

Shares held after transactions 324,147 shares Direct ownership following reported sales

Transaction count 2 sales Non-derivative open-market common stock transactions

Key Terms

Rule 10b5-1 Plan, weighted average sale price, open-market sale, Form 4

4 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.

weighted average sale price financial

"The price reported above reflects the weighted average sale 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.

Form 4 regulatory

"INSIDER FILING DATA (Form 4)"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

Form 4 Insider Transactions: What Each Field Means →

04/08/2026 - 04:19 PM

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^*

Brown Shelly

(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, Chief Strategy Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/06/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	04/06/2026		S⁽¹⁾		2,357	D	$41.33⁽²⁾	325,047	D
Common Stock	04/07/2026		S⁽¹⁾		900	D	$42	324,147	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the reporting person on December 22, 2025.

2. This transaction was executed in multiple trades throughout the day at prices ranging from $40.10 to $41.79. 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.

Remarks:

	/s/Alessandra Maria Corona Henriques, Attorney-in-Fact	04/08/2026
	** 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)

Source: View Original Filing on SEC EDGAR

FAQ

What did MIAX executive Shelly Brown do in this Form 4 filing?

Shelly Brown reported selling 3,257 shares of MIAX common stock in open-market transactions. The sales occurred on April 6 and April 7, 2026, and were recorded as routine insider transactions under SEC Form 4 reporting rules.

How many MIAX shares did Shelly Brown sell and at what prices?

She sold 2,357 shares at about $41.33 per share on April 6, 2026, and 900 shares at about $42.00 per share on April 7, 2026. In total, 3,257 MIAX common shares were sold in these transactions.

How many MIAX shares does Shelly Brown hold after these sales?

After the reported sales, Shelly Brown directly holds 324,147 shares of MIAX common stock. This figure reflects her remaining direct ownership position following the two open-market sale transactions disclosed in the Form 4 filing.

Were Shelly Brown’s MIAX stock sales under a Rule 10b5-1 plan?

Yes. The filing states that at least one transaction was executed pursuant to a previously established Rule 10b5-1 trading plan. Such plans pre-schedule trades, indicating the timing of these MIAX share sales was arranged in advance rather than decided spontaneously.

What role does Shelly Brown hold at MIAX?

Shelly Brown serves as Executive Vice President and Chief Strategy Officer at MIAX. Her Form 4 filing reports transactions in MIAX common stock, providing transparency into trades made by a senior member of the company’s leadership team.

What does a Form 4 insider sale mean for MIAX investors?

A Form 4 insider sale simply discloses that an insider traded company shares. In this case, Shelly Brown sold 3,257 MIAX shares while retaining 324,147 shares, and at least one sale was pre-planned under Rule 10b5-1, suggesting routine portfolio management.