Murray Stahl - 05 Mar 2026 Form 4 Insider Report for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX)

Reporting relationship: Director
Issuer ticker: MIAX
Reported as of: 05 Mar 2026
Net transaction value: +$310,176
SEC form: 4
Accepted by SEC: 06 Mar 2026, 17:57:15 UTC
Prior SEC filing: 06 Mar 2026
Next SEC filing: 09 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Jay Kesslen, attorney-in-fact

Key filing fact

Murray Stahl filed Form 4 for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) on 06 Mar 2026.

Key facts

This page summarizes Murray Stahl's Form 4 filing for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX).
1 reported transaction and 4 derivative rows are listed below.
Accepted by SEC: 06 Mar 2026, 17:57.

Change

Previous filing in this sequence was filed on 06 Mar 2026.
Current net transaction value: +$310,176.

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

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (2)

CIK 0001207097 Primary reporting owner

STAHL MURRAY

Relationship: Director
Address: 470 PARK AVE S, 8TH FLOOR SOUTH, NEW YORK
Signature: /s/ Jay Kesslen, attorney-in-fact
Signature date: 06 Mar 2026

CIK 0001056823

HORIZON KINETICS ASSET MANAGEMENT LLC

Relationship: 10%+ Owner
Address: 470 PARK AVE S, 8TH FLOOR SOUTH, NEW YORK
Signature: /s/ Jay Kesslen, attorney-in-fact
Signature date: 06 Mar 2026

Reported non-derivative transactions

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

MIAX transaction

Common Stock

Purchase

Transaction value: $310,176
Shares: +7,200
Change %: +0.16%
Price: $43.08
Shares after: 4,633,842
Date: 05 Mar 2026
Ownership: Horizon Kinetics Asset Management LLC
Footnotes: F1

Reported derivative securities

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

MIAX holding Derivative

Options

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 7,500
Date: 05 Mar 2026
Ownership: Direct
Underlying class: Miami International Holdings Inc
Underlying amount: 7,500
Exercise price: $16.14
Footnotes: F2

MIAX holding Derivative

Options

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 10,000
Date: 05 Mar 2026
Ownership: Direct
Underlying class: Miami International Holdings Inc
Underlying amount: 10,000
Exercise price: $25.98
Footnotes: F2

MIAX holding Derivative

Options

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 14,331
Date: 05 Mar 2026
Ownership: Direct
Underlying class: Miami International Holdings Inc
Underlying amount: 14,331
Exercise price: $19.84
Footnotes: F2

MIAX holding Derivative

Options

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 2,500
Date: 05 Mar 2026
Ownership: Direct
Underlying class: Miami International Holdings Inc
Underlying amount: 2,500
Exercise price: $16.14
Footnotes: F2

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Murray Stahl serves as Chairman, Chief Executive Officer, and Chief Investment Officer of Horizon Kinetics Asset Management LLC ("HKAM"), which manages funds and accounts (the "Managed Accounts") that hold securities of the Issuer. Mr. Stahl does not exercise investment discretion with respect to the securities of the Issuer that are beneficially owned by the Managed Accounts. Mr. Stahl disclaims beneficial ownership over the securities reported, except to the extent of his pecuniary interest therein, if any. The filing of this Form shall not be deemed an admission that the Mr. Stahl is the beneficial owner of such securities for purposes of Section 16 or any other purpose.

Footnote F2

The Options given to Mr. Stahl are fully vested.