SCHEDULE: Horizon Kinetics Boosts Stake in Miami International Holdings

Horizon Kinetics Asset Management LLC has increased its beneficial ownership in Miami International Holdings, Inc. to 12.2%, coinciding with the election of a Horizon Kinetics representative to the company's Board of Directors.

Summary

• Horizon Kinetics Asset Management LLC (HKAM), a subsidiary of Horizon Kinetics Holding Corporation (HKHC), has filed an amendment to its Schedule 13D, reporting an increased beneficial ownership of Miami International Holdings, Inc. (MIH) common stock.
• As of April 27, 2026, HKAM beneficially owned 11,162,809 shares, representing 12.2% of the outstanding common stock.
• This filing is an amendment to previous filings made on August 13, 2025, November 24, 2025, and April 14, 2026.
• On April 24, 2026, Eric Sites, a Managing Director at HKAM, was elected to the Board of Directors of MIH.
• HKAM acquired these securities on behalf of Managed Accounts for investment purposes.
• HKAM regularly reviews its equity interest in MIH and may acquire additional shares or securities in the future.
• While there is no present intention to dispose of all shares, HKAM may sell shares from time to time due to client requests, regulatory limitations, or other reasons, through open market or private transactions.

Sentiment

Score: 7

Explanation: StockSavvy.ai views this as a moderately positive development, reflecting increased investor confidence and governance involvement, though the potential for future sales introduces a note of caution.

Positives

• Increased stake in Miami International Holdings, Inc. to 12.2% by Horizon Kinetics Asset Management LLC.
• Appointment of Eric Sites, a Managing Director at Horizon Kinetics, to the Board of Directors of Miami International Holdings, Inc. on April 24, 2026, indicating increased influence and oversight.
• Continued investment activity with numerous 'BUY' transactions detailed in the 60-day trading history, suggesting confidence in the company's prospects.

Negatives

• The filing explicitly states that HKAM may sell shares from time to time, indicating potential future selling pressure.
• The beneficial ownership is held on behalf of 'Managed Accounts,' which could imply diverse underlying investor interests that may not always align with long-term strategic goals.

Risks

• HKAM may sell shares from time to time for various reasons, including client requests, regulatory or investment limitations.
• The potential for future sales of securities by HKAM could impact the stock price.
• While not explicitly stated as a risk, the election of a director from a significant shareholder could lead to governance challenges or conflicts of interest if not managed properly.

Future Outlook

Horizon Kinetics Asset Management LLC intends to regularly review its equity interest in Miami International Holdings, Inc. and may acquire additional shares or securities in the future. While there is no present intention to dispose of all shares, sales may occur from time to time.

Management Comments

• HKAM acquired the securities reported herein on behalf of the Managed Accounts for investment purposes.
• In the ordinary course of its business, HKAM intends to regularly review its equity interest in the Issuer and may, from time to time, acquire additional shares or other securities of the Issuer.
• While HKAM has no present intention to dispose of all or any portion of the shares beneficially owned by Managed Accounts, it may sell shares from time to time for a number of reasons, not limited to client requests, regulatory or investment limitations or other reasons.
• Any such sales of securities of the Issuer may be in the open market, privately negotiated transactions or otherwise.

Industry Context

StockSavvy.ai notes that significant stake increases and board representation by asset managers are common in the financial services sector, often signaling a desire for greater influence or a belief in the company's strategic direction. This filing by Horizon Kinetics suggests a deepening engagement with Miami International Holdings, Inc.

Management Changes

Stakeholder Impact

• Shareholders: Increased board representation by a significant investor may lead to enhanced oversight and potentially influence strategic decisions, which could impact shareholder value. The possibility of future sales by Horizon Kinetics could also affect share price stability.
• Employees: Changes in board composition can sometimes signal shifts in strategic direction, which may indirectly affect employees.
• Management: The appointment of Eric Sites to the board may lead to closer collaboration or increased scrutiny from Horizon Kinetics.

Next Steps

• Horizon Kinetics Asset Management LLC will continue to review its equity interest in Miami International Holdings, Inc.
• HKAM may acquire additional shares or securities of Miami International Holdings, Inc. in the future.
• HKAM may sell shares from time to time.

Key Dates

Recommendation

The filing indicates a significant increase in beneficial ownership and board representation by Horizon Kinetics, suggesting a strong conviction in the company's value. However, the explicit statement of potential future sales and the lack of specific forward-looking financial guidance prevent a stronger recommendation. A 'hold' position allows investors to monitor further developments and the impact of the new board member.

Keywords

Schedule 13D, Horizon Kinetics, Miami International Holdings, Beneficial Ownership, Eric Sites, Board of Directors, Investment, Securities, SEC Filing, Amendment