Transaction Details

Footnotes

The Reporting Person donated 500 shares of IBKR Class A common stock to a nonprofit organization. | This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the amended 2007 Stock Incentive Plan ("Plan") and (b) unvested restricted stock units that were awarded under the Plan. | Represents number of securities owned by EN Holdings LLC, which is owned by the reporting person and his affiliates. | On June 17, 2025, the Issuer effected a four-for-one split of its common stock, resulting in the reporting person's ownership of 321,234 additional shares of common stock. | On June 17, 2025, the Issuer effected a four-for-one split of its common stock, resulting in the reporting person's ownership of 300,000 additional shares of common stock.