The SEC filings of Miami International Holdings, Inc. (NYSE: MIAX) provide detailed information about its capital markets activity, segment reporting and regulatory disclosures as an exchange operator. Through documents such as Form S-1 and Form 8-K, the company describes its business structure, operating segments and equity transactions.
In its Form S-1 registration statement, Miami International Holdings identifies operating segments associated with options, equities, futures and international markets, along with a corporate/non-segment category. The filing references revenue categories including transaction and clearing fees, access fees, market data fees and other products and services, giving investors insight into how the company characterizes its exchange-related activities.
Recent Form 8-K filings highlight specific events. An 8-K dated December 15, 2025 discloses unregistered sales of equity securities, including common stock issued upon conversion of a convertible promissory note and upon warrant exercises, and notes that aggregate unregistered issuances exceeded a threshold relative to shares outstanding as of a prior date. The same filing also describes the completion of a public secondary offering in which existing stockholders sold shares of common stock, with the company stating that it did not sell shares or receive proceeds.
Other 8-K reports address topics such as quarterly financial results, changes in the board of directors and the announcement of an agreement to sell a majority stake in MIAX Derivatives Exchange (MIAXdx) to Robinhood Markets, Inc. in partnership with Susquehanna International Group. These filings illustrate how the company uses current reports to communicate material events, corporate governance changes and strategic transactions.
On Stock Titan’s MIAX filings page, users can review these SEC documents as they are made available through EDGAR. AI-powered tools can help summarize lengthy forms such as S-1 and 8-K, highlight key segment and revenue disclosures, and surface notable equity issuance and offering details, making it easier to understand the regulatory information Miami International Holdings provides.
MIAMI INTERNATIONAL HOLDINGS, INC. director Kurt M. Eckert exercised stock options for 5,625 shares of Common Stock at $12.00 per share and on the same day sold 5,625 shares in an open-market transaction.
The sale was executed at a weighted average price of $47.29 per share, with individual trades ranging from $47.09 to $47.53, under a previously established Rule 10b5-1 trading plan adopted on December 18, 2025. After these transactions, he holds 142,375 shares of Common Stock directly and 11,563 fully vested stock options expiring on May 31, 2027.
MIAMI International Holdings EVP, GC & Corporate Secretary Barbara J. Comly reported an exercise-and-sell transaction in company common stock. On May 4, 2026, she exercised 28,000 nonqualified stock options at $12.00 per share and acquired the same number of common shares.
On the same date, she executed an open-market sale of 28,000 common shares at an average price of $47.26 per share, pursuant to a pre-established Rule 10b5-1 Plan adopted on December 18, 2025. Following these transactions, she directly holds 843,844 common shares and 84,000 nonqualified stock options that are reported as fully vested.
J. Gray Teekell submitted a Form 144 notice to sell 9,000 shares of Common Stock of the issuer. The filing lists prior 10b5-1 sales of 2,700 shares on 04/02/2026 for $108,000 and 300 shares on 03/25/2026 for $12,000. The securities to be sold are identified as previously exercised stock options dated 03/27/2024.
MIAX reported a Rule 144 notice to sell 32,000 shares of Common Stock dated 05/04/2026, described as resulting from an exercise of stock options and to be sold for cash. The filing also lists recent 10b5-1 plan sales by Shelly Brown totaling 45,623 shares across 03/23/2026–04/08/2026 with disclosed proceeds.
Morgan Stanley Smith Barney LLC submitted a Rule 144 notice reporting the planned sale of 33,000 shares of Common Stock related to the exercise of stock options on 05/04/2026 with cash proceeds. The filing also lists recent 10b5-1 sales by Edward Deitzel: 7,572 shares for $318,161.05 on 04/08/2026 and 4,763 shares for $200,046.00 on 04/07/2026.
Miami International Holdings, Inc. director Eric Sites filed an initial ownership report showing fully vested nonqualified stock options linked to the company’s shares. The options cover 9,174 underlying shares at an exercise price of $20.0000, 9,554 shares at $19.8400, 7,500 shares at $25.9800, and 7,500 shares at $16.1400, all expiring on March 26, 2030. A footnote notes that Sites was elected to the Board of Directors on April 24, 2026 and that Horizon Kinetics Asset Management LLC separately reported beneficial ownership of 11,162,809 shares on an amended Schedule 13D.
Horizon Kinetics Asset Management LLC filed Amendment No. 3 to Schedule 13D reporting beneficial ownership of 11,162,809 shares of Miami International Holdings, Inc. common stock, representing 12.2% of the outstanding shares as of the close of business on April 27, 2026. Horizon Kinetics holds sole voting and dispositive power over these shares on behalf of its managed accounts, while parent company Horizon Kinetics Holding Corp may be deemed to share beneficial ownership. The filing states the position is held for investment purposes, with the flexibility to buy more or sell shares over time. On April 24, 2026, Eric Sites, a Managing Director of Horizon Kinetics Asset Management, was elected to the issuer’s Board of Directors.
Miami International Holdings, Inc. is asking stockholders to vote at its 2026 virtual annual meeting on June 16, 2026 at 8:00 a.m. Eastern Time via webcast.
Stockholders will elect 15 directors, approve on an advisory basis executive compensation, choose how often future say-on-pay votes occur, and ratify KPMG LLP as independent auditor for the year ending December 31, 2026.
Holders of 94,800,071 outstanding common shares as of April 20, 2026 are entitled to one vote per share and can vote online, by phone, mail, or during the virtual meeting.
Miami International Holdings, Inc. has elected Eric Sites to its board of directors to fill an existing vacancy. The board approved his appointment on April 23, 2026, effective April 24, 2026.
He will serve until the 2026 Annual Meeting of Shareholders, receive the same compensation as other non‑employee directors, and currently has no committee assignments. The company states he has no family relationships with its directors or executive officers and no transactions requiring disclosure under Item 404(a) of Regulation S‑K. Sites has entered into an indemnification agreement that may cover legal expenses and related costs arising from his board service.