Form 4: MIAX Director Murray Stahl Boosts Stake

Miami International Holdings, Inc. Director Murray Stahl reported an acquisition of common stock and detailed his beneficial ownership, including derivative securities.

Summary

• Murray Stahl, a Director of Miami International Holdings, Inc. (MIAX) and Chairman, Chief Executive Officer, and Chief Investment Officer of Horizon Kinetics Asset Management LLC (a 10% owner), reported changes in beneficial ownership.
• On December 12, 2025, 2,439 shares of common stock were acquired at a price of $41 per share.
• Following this transaction, the total beneficial ownership of common stock, held indirectly through Horizon Kinetics Asset Management LLC, is 4,560,364 shares.
• The filing also details fully vested options to acquire 34,331 shares of common stock with various exercise prices and expiration dates ranging from July 2031 to March 2033.
• Additionally, 112,656 vested and exercisable warrants to acquire common stock are reported, with various exercise prices and expiration dates ranging from April 2026 to February 2027.
• Mr. Stahl disclaims beneficial ownership over securities managed by Horizon Kinetics Asset Management LLC, except to the extent of his pecuniary interest.

Sentiment

Score: 7

Explanation: A director's purchase of company stock typically signals confidence in the company's future performance. The significant indirect holdings through Horizon Kinetics Asset Management LLC, despite the disclaimer, also indicate a substantial stake.

Positives

• A director and significant owner (through an affiliated entity) acquired additional common stock, signaling confidence in the company's future.
• All reported options and warrants held by Mr. Stahl are fully vested and exercisable, indicating long-term commitment and potential upside.

Risks

• The disclaimer of beneficial ownership by Mr. Stahl over the majority of the reported securities (those held by Managed Accounts) means his direct financial exposure to those specific shares is limited to his pecuniary interest, which is not quantified. This could be a minor point for some investors looking for direct insider alignment.

Future Outlook

This Form 4 filing reports past insider transactions 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 the 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 show.

Industry Context

This filing is a standard disclosure of insider trading activity. Insider purchases are often viewed by the market as a positive signal, suggesting that those with intimate knowledge of the company believe its stock is undervalued or has strong future prospects.

Related Party Transactions

• The indirect beneficial ownership of Miami International Holdings, Inc. securities through Horizon Kinetics Asset Management LLC, where Murray Stahl serves as Chairman, CEO, and CIO, constitutes a related party relationship for reporting purposes under Section 16.

Stakeholder Impact

• Shareholders may view the director's purchase as a positive indicator of management confidence, potentially leading to increased investor interest and a positive impact on share price.

Key Dates

Recommendation

The purchase of common stock by a director, especially one associated with a 10% owner, is generally a positive signal, indicating management's confidence in the company's prospects. While this single transaction doesn't warrant a 'buy' recommendation without broader financial analysis, it supports a 'hold' position for existing investors and suggests potential for future appreciation.

Keywords

MIAX, Miami International Holdings, insider trading, Form 4, beneficial ownership, stock purchase, director, Murray Stahl, Horizon Kinetics, common stock, options, warrants