Heading into the quarter, analysts forecast Interactive Brokers would earn $0.45 per share (adjusted for one-time items) on sales of just under $1.4 billion. In fact, the company earned $0.51 per share -- generally accepted accounting principles ( GAAP) -- and its sales were just under $1. 5 billion.

Interactive Brokers (IBKR) stock climbed 4.8% in Thursday after-hours trading after posting better-than-expected second-quarter headline results, bolstered by higher customer trading volume.

Interactive Brokers Group, Inc. IBKR +6.68% Get Free Report shares are trading higher Friday after the company reported better-than-expected second quarter adjusted earnings per share and sales on Thursday after the market closed.