0001381197 2026-10-15 2026-10-15 0001381197 false 8-K 2026-10-15 Interactive Brokers Group, Inc. DE 001-33440 30-0390693 ONE PICKWICK PLAZA GREENWICH CT 06830 203 618-5800 false false false false Common Stock, par value $.01 per share IBKR NASDAQ false