SCHEDULE: Horizon Kinetics Boosts Stake in Miami Intl. Holdings

Horizon Kinetics Asset Management LLC has disclosed a 10.7% beneficial ownership stake in Miami International Holdings, Inc., primarily for investment purposes.

Summary

• Horizon Kinetics Asset Management LLC (HKAM) has filed a Schedule 13D, reporting beneficial ownership of 8,679,747 shares of Miami International Holdings, Inc. Common Stock.
• This stake represents 10.7% of the Issuer's outstanding Common Stock.
• The ownership includes 8,400,880 shares held directly by Managed Accounts and warrants exercisable for 278,867 shares.
• Warrants are currently vested and exercisable until various dates ranging from April 8, 2026, to August 9, 2027.
• HKAM used approximately $65,000,000 of client assets to acquire these shares as of August 19, 2025.
• The acquisition is for investment purposes, with HKAM intending to regularly review its equity interest and potentially acquire or sell shares.
• Murray Stahl, Chairman, CEO, and CIO of HKAM, was appointed to the Issuer's Board of Directors on July 15, 2025, and may influence corporate activities.

Sentiment

Score: 7

Explanation: The filing indicates a significant, high-conviction investment by a reputable asset manager, including a board appointment, suggesting positive long-term prospects for the Issuer. No negative information or risks beyond standard investment considerations were disclosed.

Positives

• A significant institutional investor, Horizon Kinetics Asset Management LLC, has taken a substantial 10.7% stake, indicating confidence in Miami International Holdings, Inc.
• The appointment of Murray Stahl, a key executive from Horizon Kinetics, to the Issuer's Board of Directors suggests potential for strategic alignment and influence.
• Recent purchases by HKAM occurred at increasing share prices, including 850,000 shares at $23.00 on August 14, 2025, and further buys up to $34.65 on August 18, 2025, reflecting continued buying interest even as the price rose.

Risks

• HKAM may sell shares from time to time due to client requests, regulatory or investment limitations, or other reasons, which could impact share price.
• While Murray Stahl's board appointment may offer influence, his lack of investment discretion over HKAM's holdings means direct control over the stake's future is limited to HKAM's overall strategy.

Future Outlook

Horizon Kinetics Asset Management LLC intends to regularly review its equity interest in Miami International Holdings, Inc. and may, from time to time, acquire additional shares or other securities, or sell existing shares for various reasons including client requests or regulatory limitations.

Industry Context

This filing indicates a significant institutional investment in a company, likely operating in the financial services or exchange sector given its name. Such large stakes by investment managers often signal a belief in the company's long-term value or potential for strategic influence, which can be a positive signal within the broader financial industry.

Comparison to Industry Standards

• The 10.7% stake by Horizon Kinetics Asset Management LLC is a substantial position for an institutional investor, often indicative of a high-conviction investment. For comparison, activist investors typically target stakes above 5% to gain influence, while passive institutional investors might hold smaller, diversified positions.
• The appointment of Murray Stahl, a key executive from the investing firm, to the Issuer's board is a common strategy for large shareholders to gain direct oversight and influence, similar to practices seen with firms like ValueAct Capital or Pershing Square when they take significant stakes in companies like Microsoft or Chipotle.
• The reported purchase prices, ranging from $21.00 to $34.65, show Horizon Kinetics' willingness to accumulate shares even as the price increased, suggesting a strong belief in the company's intrinsic value, a pattern often observed in long-term value investing strategies.

Management Changes

Corporate Governance

Legal Proceedings

• The Reporting Person has not been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors) in the last five years.
• The Reporting Person has not been a party to any civil proceeding of a judicial or administrative body of competent jurisdiction which resulted in or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violations with respect to such laws in the last five years.

Stakeholder Impact

• Shareholders: The significant stake by a major institutional investor and the appointment of their executive to the board could be viewed positively, potentially signaling confidence and a commitment to long-term value creation. It might also lead to increased scrutiny or influence over corporate strategy.
• Management/Board: The presence of Murray Stahl on the board means management will have a direct line to a significant shareholder's perspective and potential influence on strategic decisions.

Next Steps

• Horizon Kinetics Asset Management LLC intends to regularly review its equity interest in Miami International Holdings, Inc.
• Horizon Kinetics Asset Management LLC may, from time to time, acquire additional shares or other securities of the Issuer.
• Horizon Kinetics Asset Management LLC may sell shares from time to time for various reasons.
• Horizon Kinetics Asset Management LLC may seek to influence management or the board of directors of the Issuer.

Key Dates

Recommendation

The filing reveals a substantial and increasing stake by a sophisticated institutional investor, Horizon Kinetics Asset Management LLC, which has also secured a board seat for its top executive, Murray Stahl. This indicates a high-conviction investment and potential for strategic influence, suggesting the investor sees significant long-term value. The continued buying at rising prices further reinforces this positive outlook, making it a compelling "buy" signal for other investors.

Keywords

Miami International Holdings, Horizon Kinetics, Schedule 13D, Institutional Ownership, Investment Management, Common Stock, Warrants, Corporate Governance, Board Appointment, Equity Stake