Interactive Brokers Group, Inc. is a large, technology-driven brokerage serving both retail and institutional clients, with nearly $780 billion in customer equity at the end of 2025. The company began as a market maker, helping introduce automation and algorithmic trading to U.S. financial markets before expanding into brokerage services in 1993. Interactive Brokers serves a diverse global client base and is known for top-tier order execution and very low margin lending rates, features that appeal to sophisticated users such as hedge funds, proprietary trading firms, and introducing brokers, which generate about 45% of the company’s commissions. With access to more than 170 electronic exchanges across 40 countries and 29 currencies, the firm has a broad international footprint, and over 80% of its active accounts are located outside the United States.