Form 4: MIAX Director's Entity Buys Minor Stock, Discloses Holdings

A director of Miami International Holdings, Inc. reported a minor acquisition of common stock and disclosed extensive derivative holdings through an affiliated entity.

Summary

• Murray Stahl, a director of Miami International Holdings, Inc. (MIAX), reported changes in beneficial ownership.
• Horizon Kinetics Asset Management LLC (HKAM), an entity associated with Mr. Stahl, acquired 2 shares of common stock on October 3, 2025, at a price of $41.97 per share.
• Following this transaction, HKAM beneficially owns 4,557,925 shares of common stock.
• Mr. Stahl directly holds various fully vested stock options with exercise prices ranging from $16.14 to $25.98 and expiration dates between May 31, 2031, and March 26, 2033.
• HKAM indirectly holds various vested warrants with exercise prices ranging from $15 to $20.5 and expiration dates between April 8, 2026, and February 5, 2027.
• Mr. Stahl disclaims beneficial ownership over securities held by HKAM, except to the extent of his pecuniary interest.

Sentiment

Score: 5

Explanation: The filing is a routine disclosure of insider beneficial ownership and a very minor stock acquisition. It does not contain information that significantly alters the company's fundamental outlook, hence a neutral sentiment.

Positives

• An entity associated with a director made a small purchase of common stock, indicating continued, albeit minor, insider investment.
• Significant beneficial ownership of common stock (4,557,925 shares) is held indirectly by an entity associated with a director, suggesting a substantial long-term stake.
• Director Murray Stahl holds a considerable number of fully vested stock options and warrants, aligning his interests with shareholder value creation.

Negatives

• The reported acquisition of common stock was for a very small number of shares (2 shares), which does not signal strong insider conviction or a significant change in investment strategy.

Risks

• Murray Stahl disclaims beneficial ownership over securities managed by Horizon Kinetics Asset Management LLC, except for his pecuniary interest, which could imply limited direct control or influence over these specific holdings.

Future Outlook

This filing, a Form 4, primarily reports changes in beneficial ownership and does not contain forward-looking statements or guidance regarding the company's future outlook.

Management Comments

• 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 Mr. Stahl is the beneficial owner of such securities for purposes of Section 16 or any other purpose.
• The Options given to Mr. Stahl are fully vested.
• The Warrants are currently vested and presently exercisable until the expiration date shown.

Industry Context

This Form 4 filing is a routine disclosure of insider trading activity and beneficial ownership, and as such, it does not provide specific insights into broader industry trends or competitive landscape.

Comparison to Industry Standards

• NA

Related Party Transactions

• Murray Stahl, a director of Miami International Holdings, Inc., is also Chairman, CEO, and CIO of Horizon Kinetics Asset Management LLC (HKAM), which indirectly holds a significant stake in the issuer. This establishes a related party relationship for beneficial ownership reporting.

Stakeholder Impact

• Shareholders: The minor acquisition and disclosure of existing holdings provide transparency into insider ownership but are unlikely to have a significant immediate impact on shareholder value due to the small transaction size.

Next Steps

• NA

Key Dates

Recommendation

This Form 4 filing details a minor acquisition of common stock by an entity associated with a director and discloses existing derivative holdings. The transaction size is too small to indicate a significant change in insider sentiment or company fundamentals, thus a 'hold' recommendation is appropriate based solely on this filing.

Keywords

MIAX, Form 4, insider transaction, beneficial ownership, Murray Stahl, Horizon Kinetics Asset Management, stock options, warrants