Douglas M. Schafer Jr., EVP and CIO of Miami International Holdings, Inc., filed a Form 4 on October 26, 2026, reporting the exercise of 8,000 stock options and the same-day sale of 8,000 shares of common stock on October 22, 2026, under a pre-established Rule 10b5-1 plan.

Key Highlights

  • Option exercise: Schafer exercised 8,000 nonqualified stock options at an exercise price of $12.00 per share on October 22, 2026.
  • Shares sold: 8,000 shares of common stock were disposed of at a weighted average price of $35.06, with individual trade prices ranging from $35.00 to $35.14.
  • 10b5-1 plan: Both transactions were made pursuant to a Rule 10b5-1 plan adopted by Schafer on December 16, 2025.
  • Remaining common stock: Following the transactions, Schafer directly holds 387,414 shares of common stock.
  • Remaining options: Schafer retains 147,334 nonqualified stock options, which are fully vested, with an exercise price of $12.00 and an expiration date of July 31, 2029.

Schafer's October 22 Option Exercise and Share Sale at Miami International Holdings

According to the filing, Douglas M. Schafer Jr., serving as Executive Vice President and Chief Information Officer of Miami International Holdings, Inc. (MIAX), executed a two-part transaction on October 22, 2026. He first acquired 8,000 shares of common stock through the exercise of nonqualified stock options at an exercise price of $12.00 per share, bringing his direct beneficial ownership to 395,414 shares at that point.

Immediately following the option exercise, the filing reports that Schafer disposed of 8,000 shares of common stock. The sale was executed in multiple trades throughout the day at prices ranging from $35.00 to $35.14, with the weighted average sales price reported as $35.06. After this disposal, his direct beneficial ownership in common stock stood at 387,414 shares, according to the filing. The reporting person has undertaken to provide full information on individual trade prices and share counts upon request to the SEC staff, the issuer, or a security holder.

The filing notes that the exercised options were fully vested and that 147,334 nonqualified stock options remain directly held by Schafer, carrying the same $12.00 exercise price and expiring on July 31, 2029. Both the option exercise and the share sale are disclosed as having been effected pursuant to a Rule 10b5-1 plan that Schafer adopted on December 16, 2025. The Form 4 was signed by Alessandra Henriques Corona as attorney-in-fact on October 26, 2026.

What Was Disclosed

The filing discloses a same-day option exercise and share sale by Miami International Holdings EVP and CIO Douglas M. Schafer Jr. on October 22, 2026, carried out under a pre-established Rule 10b5-1 plan, with resulting direct ownership of 387,414 common shares and 147,334 remaining options.