SCHEDULE: MIHI CEO's Significant Stake Post-IPO

Miami International Holdings, Inc. CEO Thomas P. Gallagher and Gallagher Investments LLC disclose significant beneficial ownership in the company's common stock.

Summary

• Thomas P. Gallagher, Chairman and Chief Executive Officer of Miami International Holdings, Inc., and Gallagher Investments LLC are the reporting persons.
• Mr. Gallagher's principal occupation is Chairman and CEO of the Issuer, and Gallagher Investments LLC holds his investments.
• The Reporting Persons beneficially own an aggregate of 4,226,457 shares of Common Stock.
• This aggregate ownership represents 5.1% of the class for Thomas P. Gallagher and 4.3% for Gallagher Investments LLC, based on 80,947,066 shares outstanding as of August 15, 2025.
• The securities were acquired for investment purposes and are intended to be held as a long-term investment.
• Reporting Persons may continuously review their investment and may acquire additional securities or dispose of current holdings in the future.
• Mr. Gallagher, in his capacity as Chairman and CEO, may have influence over the corporate activities of the Issuer.
• The Reporting Persons have agreed to a 180-day lock-up period from the Issuer's initial public offering date, restricting the sale or transfer of their shares.

Sentiment

Score: 7

Explanation: The filing indicates strong insider commitment through significant beneficial ownership by the CEO and his investment vehicle, held for long-term investment. This aligns management's interests with shareholders, which is generally viewed positively. However, the filing does not contain operational or financial performance data to assess the company's health beyond this ownership structure.

Positives

• Significant insider ownership (5.1% of common stock) by the Chairman and CEO, Thomas P. Gallagher, and his investment entity, aligning management interests with shareholders.
• Stated intention to hold securities as a long-term investment, indicating confidence in the company's future.
• Acquisition of shares through personal funds and compensation, further demonstrating commitment.

Negatives

• No specific negatives are identified in this Schedule 13D filing, as it primarily reports beneficial ownership and investment intent rather than operational or financial performance.

Risks

• Reporting Persons reserve the right to change their investment intentions, including acquiring additional securities or disposing of current holdings, which could impact market dynamics.
• Mr. Gallagher, as Chairman and CEO, may have influence over corporate activities, potentially including significant transactions or strategic shifts.
• A significant block of shares held by insiders will become available for sale after the 180-day lock-up period expires, which could potentially increase market supply and impact the share price.

Future Outlook

Reporting Persons intend to continuously review their investment in the Issuer and may acquire additional securities or dispose of existing ones. Mr. Gallagher, as CEO, may influence future corporate activities.

Management Comments

• "We acquired all of our securities for investment purposes only and are being held as a long-term investment."
• "We intend to continuously review our investment in the Issuer and may in the future determine to acquire additional securities of the Issuer or dispose of the securities of the Issuer owned by us or take any other available course of action."
• "Mr. Gallagher is the Chairman and Chief Executive Officer of the Issuer and acquired his securities in that capacity. As a result, Mr. Gallagher may have influence over the corporate activities of the Issuer."

Industry Context

This filing reflects a standard disclosure of significant insider ownership following an Initial Public Offering (IPO) for a financial services company, likely an exchange operator. High insider ownership can be seen positively as it aligns management's interests with shareholders, a common practice in the financial industry where founders often retain significant stakes post-IPO.

Comparison to Industry Standards

• The beneficial ownership of 5.1% by the CEO and his investment entity is a substantial stake for a newly public company, often seen as a positive indicator of management's long-term commitment compared to industry peers where founders might dilute their stake more significantly post-IPO.
• The 180-day lock-up agreement is a standard practice for IPOs, aligning with typical underwriting agreements to stabilize the stock price post-listing, similar to lock-up periods observed in recent financial technology or exchange operator IPOs like Nasdaq (NDAQ) or Cboe Global Markets (CBOE) during their respective public offerings.

Management Changes

Corporate Governance

Legal Proceedings

• Neither Reporting Person has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) during the past five years.
• Neither Reporting Person was a party to a civil proceeding or a judicial or administrative body of competent jurisdiction resulting in a judgment, decree, or final order related to federal or state securities laws in the past five years.

Related Party Transactions

• Mr. Gallagher acquired Common Stock beneficially owned by him as compensation for serving as an executive officer, chairman, and co-founder of the Issuer.
• On August 11, 2025, Mr. Gallagher transferred shares and options to Gallagher Investments LLC, an entity whose principal business is holding Mr. Gallagher's investments.
• Mr. Gallagher has in the past and may receive future compensation in the form of Common Stock, options, or other securities convertible into Common Stock from the Issuer.

Stakeholder Impact

• Shareholders: The significant insider ownership and long-term investment intent by the CEO may instill confidence. However, the expiration of the 180-day lock-up period could lead to increased share availability and potential price volatility.
• Management/Employees: Reinforces the CEO's commitment to the company's long-term success and aligns his interests with the company's performance.

Next Steps

• Reporting Persons intend to continuously review their investment in the Issuer.
• Reporting Persons may acquire additional securities or dispose of existing securities in the future.
• The 180-day lock-up period will expire, after which shares may be sold.

Key Dates

Recommendation

The filing is a Schedule 13D, primarily disclosing beneficial ownership by the CEO and his investment entity. It indicates a significant insider stake and a long-term investment intent, which is generally positive for aligning management and shareholder interests. However, it does not provide new financial or operational data to warrant a 'buy' or 'sell' recommendation. The 180-day lock-up period is a standard post-IPO measure. Therefore, a 'hold' recommendation is appropriate as investors should await further financial disclosures to assess the company's performance and valuation.

Keywords

Miami International Holdings, MIHI, Thomas P. Gallagher, Gallagher Investments, Schedule 13D, beneficial ownership, insider ownership, common stock, IPO, lock-up agreement, financial services, exchange operator