FISV vs IBKR Comparison

Fiserv is a leading provider of core processing and complementary services, such as electronic funds transfer, payment processing, and loan processing, for US banks and credit unions, with a focus on small and midsize banks. Following its 2019 merger with First Data, Fiserv also provides payment processing services to merchants. About 10% of the company's revenue is generated internationally.

Interactive Brokers is a large, automated, retail and institutional brokerage that boasted nearly $780 billion in customer equity at the end of 2025. The company cut its teeth as a market maker, introducing US financial markets to automated and algorithmic training before expanding into brokerage services in 1993. The firm has a wide-ranging client base, with its best-in-class order execution and extremely low margin lending rates catering to a sophisticated audience of hedge funds, proprietary traders, and introducing brokers that account for about 45% of the firm's commissions. With operations spanning more than 160 electronic exchanges, 36 countries, and 28 currencies, Interactive Brokers caters to a global clientele, with more than 80% of active accounts sitting outside the US.