Barbara J. Comly converted fully vested incentive stock options into common stock at $12 per share, bringing her direct holdings to over 845,000 shares.

March 11, 2026

A senior executive at Miami International Holdings, Inc. (MIAX) exercised a series of incentive stock options on March 9, 2026, acquiring a total of 33,332 shares of common stock at an exercise price of $12 per share.

Barbara J. Comly, who serves as Executive Vice President, General Counsel, and Corporate Secretary at the exchange operator, carried out three separate option exercises on the same date. The transactions broke down as follows:

• 8,333 shares from an option tranche expiring August 2, 2026
• 8,333 shares from an option tranche expiring July 31, 2029
• 16,666 shares from an option tranche expiring May 28, 2028

All three exercises were conducted at a strike price of $12, putting the total transaction value at approximately $399,984. Each of the option grants was fully vested at the time of exercise, and all derivative positions were reduced to zero following the conversions.

Post-IPO Option Conversion

Notably, the options were originally granted as the right to purchase nonvoting common stock. Upon the closing of the company’s initial public offering, these instruments automatically converted into rights to acquire standard common stock at the same price and under identical terms.

Updated Holdings

Following the completion of all three transactions, Comly held 845,292 shares of common stock directly. The significant position reflects substantial equity accumulation by one of the company’s most senior legal and governance officers.

Miami International Holdings operates several options and equities exchanges and is headquartered in Princeton, New Jersey. The company trades under the ticker symbol MIAX. The transactions appear to represent routine exercises by a long-tenured insider converting vested compensation into equity, signaling continued alignment between executive holdings and shareholder interests.

The disclosure was signed on March 10, 2026, one day after the transactions were completed.