Judson Gray Teekell - 13 Aug 2025 Form 3 Insider Report for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX)

Reporting relationship: Director
Issuer ticker: MIAX
Reported as of: 13 Aug 2025
Net transaction value: $0
SEC form: 3
Accepted by SEC: 13 Aug 2025, 17:10:00 UTC
Next SEC filing: 19 Aug 2025
Source filing: View source filing
Reporting owner signature: /s/Alessandra Maria Corona Henriques, Attorney-in-Fact

Key filing fact

Judson Gray Teekell filed Form 3 for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) on 13 Aug 2025.

Key facts

This page summarizes Judson Gray Teekell's Form 3 filing for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX).
0 reported transactions and 13 derivative rows are listed below.
Accepted by SEC: 13 Aug 2025, 17:10.

Change

No earlier filing in this sequence is available for direct comparison.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Official SEC source

Ownership activity is grounded in SEC Form 3 disclosures.

View source filing

Reporting Owners (1)

CIK 0001959770 Primary reporting owner

Teekell Judson Gray

Relationship: Director
Address: C/O MIAMI INTERNATIONAL HOLDINGS, INC., 7 ROSZEL ROAD, SUITE 1A, PRINCETON
Signature: /s/Alessandra Maria Corona Henriques, Attorney-in-Fact
Signature date: 13 Aug 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MIAX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 1,096
Date: 13 Aug 2025
Ownership: Direct

MIAX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 18,414
Date: 13 Aug 2025
Ownership: By estate of Byrum W. Teekell
Footnotes: F1

MIAX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 57,219
Date: 13 Aug 2025
Ownership: By Teekell Oil & Gas, Inc.
Footnotes: F2

MIAX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 149,744
Date: 13 Aug 2025
Ownership: By Teekell Investments, LP
Footnotes: F3

MIAX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 18,639
Date: 13 Aug 2025
Ownership: By White Knight Communications, LP
Footnotes: F4

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

MIAX holding Derivative

Series B Preferred Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 30,000
Exercise price
Footnotes: F5

MIAX holding Derivative

Nonvoting Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 31,242
Exercise price
Footnotes: F6

MIAX holding Derivative

Series B Preferred Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: By estate of Byrum W. Teekell
Underlying class: Common Stock
Underlying amount: 30,000
Exercise price
Footnotes: F5, F7

MIAX holding Derivative

Nonvoting Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: By estate of Byrum W. Teekell
Underlying class: Common Stock
Underlying amount: 138,131
Exercise price
Footnotes: F6, F8

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 22,667
Exercise price: $12.00
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 13,500
Exercise price: $12.00
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 12,833
Exercise price: $12.00
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 12,500
Exercise price: $12.00
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 5,000
Exercise price: $12.00
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 28,125
Exercise price: $14.00
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Nonvoting Common Stock
Underlying amount: 20,556
Exercise price: $16.14
Footnotes: F9

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 9,247
Exercise price: $25.98
Footnotes: F10

MIAX holding Derivative

Stock Option (Right to Buy)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 13 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 5,783
Exercise price: $19.84
Footnotes: F10

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 10 footnotes

Footnote F1

18,414 shares of common stock held in the estate of Byrum W. Teekell for which J. Gray Teekell is executor and disclaims beneficial ownership as to 13,811 shares of common stock. The inclusion of such 13,811 shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F2

57,219 shares of common stock held by Teekell Oil & Gas, Inc. as to which J. Gray Teekell is the president and a stockholder and disclaims beneficial ownership as to 42,914 of such shares. The inclusion of such 42,914 shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F3

149,744 shares of common stock held by Teekell Investments, LP as to which J. Gray Teekell is a limited partner and successor trustee of the trust that serves as its general partner and he disclaims beneficial ownership as to 112,308 of such shares. The inclusion of such 112,308 shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F4

18,639 shares of common stock, held by White Knight Communications, LP in which J. Gray Teekell is a limited partner and successor trustee of the trust that serves as its general partner and he disclaims beneficial ownership as to 16,309 of such shares. The inclusion of such 16,309 shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F5

The shares of Series B Preferred Stock are convertible on a one-for-one basis into shares of common stock commencing at the time of the Company's initial public offering ("IPO") effective date, which is August 13, 2025. The Series B Preferred Stock has no expiration date.

Footnote F6

The shares of nonvoting common stock are convertible on a one-for-one basis into shares of common stock commencing at any time. The nonvoting common stock has no expiration date.

Footnote F7

30,000 shares of Series B preferred stock, held in the estate of Byrum W. Teekell for which J. Gray Teekell is executor and disclaims beneficial ownership as to 22,500 shares of Series B preferred stock. The inclusion of such 22,500 shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F8

38,132 shares of nonvoting common stock held in the estate of Byrum W. Teekell for which J. Gray Teekell is executor and disclaims beneficial ownership as to 28,599 shares of nonvoting common stock. The inclusion of such 28,599 shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F9

The options are fully vested. The options were granted initially as the right to buy nonvoting common stock. On the closing date of the IPO, these will convert to the right to buy common stock instead of nonvoting common stock.

Footnote F10

The options are fully vested.

SEC remarks

See Exhibit 24.1 - Power of Attorney

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