IBKR · Interactive Brokers Group, Inc.

This amount includes (a) securities acquired by the Reporting Person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the 2007 Stock Incentive Plan as amended ("Plan"); and (c) unvested restricted stock units that were awarded under the Plan.

This amount includes (a) securities acquired by the Reporting Person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the 2007 Stock Incentive Plan as amended ("Plan"); and (c) unvested restricted stock units that were awarded under the Plan.

The price represents the closing price of the issuer's Class A common stock as of May 8, 2026, the vesting date.

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.

The price represents the closing price of the issuer's Class A common stock as of May 8, 2026, the vesting date.

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.

The price represents the closing price of the issuer's Class A common stock as of May 8, 2026, the vesting date.

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.

The price represents the closing price of the issuer's Class A common stock as of May 8, 2026, the vesting date.

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.

The price represents the closing price of the issuer's Class A common stock as of May 8, 2026, the vesting date.

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.

This amount includes (a) securities acquired by the Reporting Person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the 2007 Stock Incentive Plan as amended ("Plan"); and (c) unvested restricted stock units that were awarded under the Plan.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $76.87 to $77.04. The Reporting Person undertakes to provide Interactive Brokers Group, Inc. (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in this footnote (1).

This amount includes (a) securities acquired by the Reporting Person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the 2007 Stock Incentive Plan as amended ("Plan"); and (c) unvested restricted stock units that were awarded under the Plan.

This amount includes (a) securities acquired by the Reporting Person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the 2007 Stock Incentive Plan as amended ("Plan"); and (c) unvested restricted stock units that were awarded under the Plan.

This amount includes (a) securities acquired by the Reporting Person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the 2007 Stock Incentive Plan as amended ("Plan"); and (c) unvested restricted stock units that were awarded under the Plan.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $74.55 to $75.54.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $75.55 to $75.99.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $77.46 to $78.41.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $76.46 to $77.45.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $75.46 to $76.45. The Reporting Person undertakes to provide Interactive Brokers Group, Inc. (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in footnotes (2) - (4) to this Form 4.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $77.02 to $78.01.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $78.02 to $78.44.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $76.45 to $77.34. The Reporting Person undertakes to provide Interactive Brokers Group, Inc. (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in footnotes (2) - (4) to this Form 4.

Represents number of securities owned by EN Holdings LLC, which is owned by the Reporting Person and his affiliates.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

The Issuer's Board also increased the annual awards granted to all directors on December 31 of each year, under the Plan, from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The annual awards granted to all directors on December 31 of each year, under the 2007 Stock Incentive Plan as amended ("Plan"), increased from $25,000 to $50,000. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which vested on January 1, 2026.

The price represents the closing price of the Issuer's Class A common stock on December 31, 2025.

This amount includes (a) securities acquired by the Reporting Person (b) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (c) unvested restricted stock units that were awarded under the Plan.

On January 22, 2026, Interactive Brokers Group, Inc.'s ("Issuer") Board of Directors ("Board") modified the compensation policy for members of the Board. The Issuer's Board, under the 2007 Stock Incentive Plan as amended ("Plan"), increased the one-time award granted to external directors on December 31 of the year of appointment from $75,000 to $100,000, retroactive to December 31, 2025. This represents additional restricted stock units granted to the Reporting Person, under the Plan, which will vest in five equal installments, beginning December 31, 2026.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the Plan for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents a grant of restricted stock units under the 2007 Stock Incentive Plan as amended ("Plan") that will vest 20% on or about 5/9/2026 and 20% on each of the first four anniversaries of 5/9/2026.

On June 17, 2025, the issuer effected a four-for-one split of its common stock, resulting in the Reporting Person's indirect ownership of 108,804 additional shares of common stock.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the amended 2007 Stock Incentive Plan ("Plan") for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

On June 17, 2025, the issuer effected a four-for-one split of its Class A common stock, resulting in the Reporting Person's ownership of 1,701 additional shares of Class A common stock.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents a grant of restricted stock units under the 2007 Stock Incentive Plan as amended ("Plan") that will vest 20% on or about 5/9/2026 and 20% on each of the first four anniversaries of 5/9/2026.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the Plan for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the Plan for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the Plan for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents a grant of restricted stock units under the 2007 Stock Incentive Plan as amended ("Plan") that will vest in five equal installments, beginning December 31, 2026.

This amount includes unvested restricted stock units that were awarded under the Plan.

This represents a grant of restricted stock units under the 2007 Stock Incentive Plan as amended ("Plan") that will vest 20% on or about 5/9/2026 and 20% on each of the first four anniversaries of 5/9/2026.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the amended 2007 Stock Incentive Plan for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

This represents an annual grant of restricted stock units under the amended 2007 Stock Incentive Plan ("Plan") for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

On June 17, 2025, the issuer effected a four-for-one split of its Class A common stock, resulting in the Reporting Person's ownership of 7,011 additional shares of Class A common stock.

This represents a grant of restricted stock units under the 2007 Stock Incentive Plan as amended ("Plan") that will vest 20% on or about 5/9/2026 and 20% on each of the first four anniversaries of 5/9/2026.

On June 17, 2025, the issuer effected a four-for-one split of its common stock, resulting in the Reporting Person's indirect ownership of 201,978 additional shares of common stock.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the amended 2007 Stock Incentive Plan ("Plan") for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

This amount includes (a) securities acquired by the reporting person; (b) Class A common stock attributable to vested restricted stock units that were awarded under the Plan; and (c) unvested restricted stock units that were awarded under the Plan.

This represents a grant of restricted stock units under the 2007 Stock Incentive Plan as amended ("Plan") that will vest 20% on or about 5/9/2026 and 20% on each of the first four anniversaries of 5/9/2026.

This amount includes (a) Class A common stock attributable to vested restricted stock units that were awarded under the Plan and (b) unvested restricted stock units that were awarded under the Plan.

This represents an annual grant of restricted stock units under the amended 2007 Stock Incentive Plan ("Plan") for being a member of the issuer's Board of Directors, which vested immediately on 12/31/2025.

The price represents the closing price of the issuer's Class A common stock on December 31, 2025.

On June 17, 2025, the issuer effected a four-for-one split of its Class A common stock, resulting in the Reporting Person's ownership of 7,011 additional shares of Class A common stock.

On June 17, 2025, the Issuer effected a four-for-one split of its common stock, resulting in the Reporting Person's indirect ownership of 671,766 additional shares of common stock.

On December 29, 2025, an immediate family member of the Reporting Person transferred 895,688 shares of the Issuer's Class A common stock to an annuity trust of which the Reporting Person is not a beneficiary. The Reporting Person has no investment control over the securities in the trust and no longer has a pecuniary interest in those shares.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.71 to $69.20. The Reporting Person undertakes to provide Interactive Brokers Group, Inc. (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in this footnote (1).

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.15 to $69.18.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.63 to $69.82. The Reporting Person undertakes to provide Interactive Brokers Group, Inc. (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in footnotes (1) - (2) to this Form 4.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.50 to $68.53.