Miami International (MIAX) director sells 3,000 shares via 10b5-1 plan

Rhea-AI Filing Summary

Miami International Holdings director Judson Gray Teekell reported an open-market sale of 3,000 shares of Common Stock on May 4, 2026 at a weighted average price of $47.30 per share, with individual trades executed between $47.14 and $47.55.

After this sale, he directly holds 56,338 shares of MIAX common stock. The transaction was carried out under a previously established Rule 10b5-1 trading plan adopted on December 17, 2025, indicating it was pre-scheduled rather than timed discretionarily.

Insider Trade Summary 10b5-1

Net Seller: 3,000 shares ($141,900)

Net Sell 1 txn

Insider Teekell Judson Gray

Role null

Sold 3,000 shs ($142K)

Type	Security	Shares	Price	Value
Sale	Common Stock	3,000	$47.30	$142K

Holdings After Transaction: Common Stock — 56,338 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 17, 2025. This transaction was executed in multiple trades throughout the day at prices ranging from $47.14 to $47.55. 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: 3,000 shares Weighted average sale price: $47.30 per share Post-transaction holdings: 56,338 shares +2 more

5 metrics

Shares sold 3,000 shares Open-market sale on May 4, 2026

Weighted average sale price $47.30 per share Common Stock sale on May 4, 2026

Post-transaction holdings 56,338 shares Direct ownership after sale

Intraday price range $47.14–$47.55 per share Prices of individual trades in sale

Rule 10b5-1 plan adoption date December 17, 2025 Plan governing the May 4, 2026 sale

Key Terms

Rule 10b5-1 Plan, open-market sale, weighted average sale price, non-derivative

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.

open-market sale financial

"transaction_action: "open-market sale" and transaction_code_description: "Sale in open market or private transaction""

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.

weighted average sale price financial

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

non-derivative financial

"transaction_type: "non-derivative" for the Common Stock sale entry"

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^*

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)
05/04/2026

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	05/04/2026		S(1)		3,000	D	$47.3(2)	56,338	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

Explanation of Responses:

1. This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 17, 2025.

2. This transaction was executed in multiple trades throughout the day at prices ranging from $47.14 to $47.55. 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	05/05/2026
	** 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 transaction did MIAX director Judson Gray Teekell report?

Judson Gray Teekell reported selling 3,000 shares of MIAX Common Stock in an open-market transaction. The sale occurred on May 4, 2026, and was executed under a previously established Rule 10b5-1 trading plan, indicating it was pre-scheduled rather than a discretionary trade.

At what price did MIAX director Teekell sell his 3,000 shares?

Teekell’s 3,000 MIAX shares were sold at a weighted average price of $47.30 per share. Footnotes state the trades occurred in multiple executions throughout the day, at prices ranging from $47.14 to $47.55, reflecting typical intraday price variation in open-market activity.

How many MIAX shares does Judson Gray Teekell hold after this Form 4 sale?

Following the reported sale, Teekell directly holds 56,338 shares of MIAX Common Stock. This figure reflects his remaining direct ownership after disposing of 3,000 shares on May 4, 2026, as disclosed in the Form 4’s post-transaction holdings column for non-derivative securities.

Was the MIAX insider sale by Teekell made under a Rule 10b5-1 plan?

Yes. A footnote explains the transaction was effected under a previously established Rule 10b5-1 Plan adopted on December 17, 2025. Such plans allow insiders to pre-schedule trades, which can reduce the significance of the specific timing of individual sales for market interpretation.

What does the Form 4 reveal about the type of MIAX insider transaction?

The Form 4 shows an open-market sale of MIAX Common Stock, coded as “S” for sale. It covers a single non-derivative transaction of 3,000 shares, with no derivative exercises or tax-withholding dispositions reported, and no remaining derivative positions listed in the derivative summary.