MIAX (Miami International Holdings) builds and operates regulated financial exchanges. Its core business is U.S. listed options, where it runs four electronic exchanges — MIAX Options, MIAX Pearl, MIAX Emerald, and MIAX Sapphire — that together held 17.1% of the U.S. multi-listed options market in 2025, reaching a record 18.2% in Q4 2025. Options exchanges match buyers and sellers of standardized contracts on stocks, ETFs, and indexes, with market makers posting continuous quotes and the exchange collecting fees on each transaction. MIAX's customers are broker-dealers, proprietary trading firms, market makers, and hedge funds; the company had 75 member firms as of year-end 2025. Beyond options, MIAX also operates a small U.S. equities exchange (roughly 1% market share), a vertically integrated futures exchange and clearinghouse (MIAX Futures), and two international listing venues — the Bermuda Stock Exchange, which dominates global insurance-linked securities listings, and The International Stock Exchange in Guernsey, a European professional bond market acquired in mid-2025. Revenue comes from transaction fees (the primary driver, tied to industry volume and MIAX's market share), access fees, market data, and listing fees. MIAX's technology platform is shared across its exchanges, giving it operating leverage as volumes grow. The business is positively exposed to market volatility, as higher volatility drives options volumes industrywide. MIAX's most significant near-term growth initiative is a planned Q2 2026 launch of Bloomberg Index futures, targeting retail traders with low-cost alternatives to CME's dominant equity index futures.