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. (MIAX) director Judson Gray Teekell reported selling a total of 8,545 shares of common stock on September 2, 2026. This included 5,545 indirectly held shares sold in his capacity as Executor of the Estate of Byrum W. Teekell and 3,000 directly held shares sold under a previously established Rule 10b5-1 Plan. After these transactions, he reported holding 81,000 shares indirectly through the estate and 69,251 shares directly. Both sales were executed in multiple trades during the day at weighted average prices.
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) is the issuer for a proposed Rule 144 sale by Gallagher Investments LLC. Gallagher Investments LLC has notified that it intends to sell 141,000 shares of common stock, to be received upon the exercise of stock options, with an aggregate market value of $5,727,420. The notice lists 99,230,898 shares outstanding of the same class as of September 3, 2026; this is a baseline figure, not the amount being sold. Prior 10b5‑1 plan sales by Gallagher Investments LLC over the past three months are also reported.
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) reported insider transactions by Chairman & CEO Thomas P. Gallagher, effected through Gallagher Investments, LLC. On August 19, 2026, the entity sold 149,700 shares of common stock at a weighted average price of $41.13 per share under a previously adopted Rule 10b5-1 Plan. On August 18, 2026, 150,300 shares were surrendered to the company to satisfy tax withholding obligations upon net settlement of restricted stock awards, which is disclosed as not representing a market sale. Gallagher is stated to maintain beneficial ownership, including voting and dispositive control, over Gallagher Investments, LLC.
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) reported an insider equity-tax event by executive officer Barbara J. Comly (EVP, GC & Corporate Secretary). On 2026-08-18, 43,420 shares of common stock at $42.41 per share were surrendered to the company to satisfy tax withholding on restricted stock awards, leaving her with 839,564 shares held directly; this was not an open-market sale.
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) received a notice that Gallagher Investments LLC intends to sell up to 149,700 shares of common stock under Rule 144. The proposed sale is to be executed through Morgan Stanley Smith Barney LLC, with the common stock listed on the NYSE.
Gallagher Investments LLC previously executed multiple Rule 10b5-1 plan sales of MIAX common stock over the past three months, each with specified share amounts and aggregate dollar values.
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) director Cynthia Schwarzkopf reported an option exercise-and-sale sequence involving 5,000 shares. She exercised 5,000 stock options at an exercise price of $12.00 per share, then sold 5,000 common shares at a weighted average price of $42.85 per share in trades ranging from $42.54–$43.33. Following the exercise, she held 11,916 stock options directly, and these transactions were effected under a previously established Rule 10b5-1 Plan adopted on March 12, 2026.
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) reported that EVP and CFO Lance Emmons sold 35,000 shares of common stock on 2026-08-17 in an open-market transaction at a weighted average price of $42.83 per share. After this sale, he directly holds 86,538 shares. The sale was executed under a previously established Rule 10b5-1 trading plan adopted on December 17, 2025, and was completed in multiple trades at prices ranging from $42.23 to $43.54.
MIAX filed to permit the resale of 35,000 shares of its common stock through J.P. Morgan Securities LLC at 270 Park Avenue, New York. The filing lists an aggregate market value of about $1,523,200 and a CUSIP-related value reference of 99,230,898, with an indicative date of 08/17/2026 on the NYSE. The shares relate to previously granted equity compensation, including vested restricted stock awards from 2024 and 2025.
T. Rowe Price Investment Management, Inc., a Maryland corporation, filed a Schedule 13G reporting a significant position in Miami International Holdings common stock. The firm reports beneficial ownership of 5,032,970 shares, representing 5.3% of the class.
T. Rowe Price Investment Management reports sole voting power5,019,927 shares and sole dispositive power5,032,970 shares, with no shared voting or dispositive power. The firm expressly states that this filing should not be construed as an admission that it is the beneficial owner of these securities and that such beneficial ownership is denied.
Miami International Holdings, operator of options, equities, futures and international exchanges, reported strong growth for the three months ended June 30, 2026. Total revenues were 387,629 (dollars in thousands), up from 327,784, with revenues less cost of revenues rising to 141,113 from 104,662. Operating income was 27,797, roughly flat year over year, but net income increased to 44,208 and diluted EPS to 0.40.
For the first half of 2026, net income jumped to 214,432 (thousands) and diluted EPS to 1.95, compared with 2,107 and 0.03 a year earlier. Drivers included higher segment revenues, a 50,570 gain on the sale of 90% of MIAXdx to a Robinhood–SIG joint venture and an 85,603 income tax benefit, partly offset by a 30,000 litigation settlement with Nasdaq.
Cash, cash equivalents, segregated cash and restricted cash reached 804,289 at June 30, 2026, while total stockholders’ equity rose to 1,150,301. Debt consisted mainly of a 1,514 notes payable balance. Net cash provided by operating activities was 183,642 for the half year, and total cash and related balances increased by 246,705.