CME

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

At the Reporting Person's election, shares issued in lieu of all or a portion of the annual cash retainer for serving as a member of the Board of Directors. The number of shares was determined by dividing the cash retainer by the closing price on the date of grant.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

At the Reporting Person's election, shares issued in lieu of all or a portion of the annual cash retainer for serving as a member of the Board of Directors. The number of shares was determined by dividing the cash retainer by the closing price on the date of grant.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

At the Reporting Person's election, shares issued in lieu of all or a portion of the annual cash retainer for serving as a member of the Board of Directors. The number of shares was determined by dividing the cash retainer by the closing price on the date of grant.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents shares acquired pursuant to a broker-administered dividend reinvestment plan.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents shares acquired pursuant to a broker-administered dividend reinvestment plan.

At the Reporting Person's election, shares issued in lieu of all or a portion of the annual cash retainer for serving as a member of the Board of Directors. The number of shares was determined by dividing the cash retainer by the closing price on the date of grant.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

At the Reporting Person's election, shares issued in lieu of all or a portion of the annual cash retainer for serving as a member of the Board of Directors. The number of shares was determined by dividing the cash retainer by the closing price on the date of grant.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

Represents a grant of fully vested shares of Class A Common Stock issued to the Reporting Person as part of the Issuer's annual equity compensation program for non-employee directors under the CME Group Director Stock Plan. These shares are not subject to any vesting conditions.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $298.00 to $298.89, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $299.00 to $299.95, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

Represents a pro-rata, in-kind distribution of Class A Common Stock by WH Trading LLC to the Reporting Person for no consideration in a transaction exempt under Rule 16a-13. The Reporting Person received 20,320 shares in his individual capacity, which are now held directly. Previously, such shares were reported as being held indirectly by the Reporting Person. Effective May 1, 2026, the Reporting Person is no longer the managing member of WH Trading LLC. As a result of his retirement, the Reporting Person no longer shares voting or dispositive power over, or holds a reportable pecuniary interest in, the shares held of record by WH Trading LLC.

Represents a pro-rata, in-kind distribution of Class A Common Stock by WH Trading LLC to the Reporting Person for no consideration in a transaction exempt under Rule 16a-13. The Reporting Person received 20,320 shares in his individual capacity, which are now held directly. Previously, such shares were reported as being held indirectly by the Reporting Person. Effective May 1, 2026, the Reporting Person is no longer the managing member of WH Trading LLC. As a result of his retirement, the Reporting Person no longer shares voting or dispositive power over, or holds a reportable pecuniary interest in, the shares held of record by WH Trading LLC.

The amount of securities beneficially owned reported in Column 5 has been adjusted to reflect an administrative tracking true-up of 20.531 shares due to a cumulative clerical error in the calculation of historical balances. This adjustment reflects the Reporting Person's actual beneficial ownership as of the date of this filing.

Reflects shares that were acquired pursuant to a dividend reinvestment plan administered by the reporting person's broker. Actual amounts of fractional shares owned may vary slightly due to rounding.

Reflects shares that were acquired pursuant to a dividend reinvestment plan administered by the reporting person's broker. Actual amounts of fractional shares owned may vary slightly due to rounding.

This transaction was effected pursuant to a Rule 10b5-1 plan adopted by the reporting person on February 18, 2025.

This amendment is being filed to correct the price per share of the common stock sold on March 17, 2026, which was incorrectly reported on the original Form 4 filed on March 19, 2026 due to a clerical error. All other information in the original Form 4 remains unchanged.

Mr. Marcus surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Mr. McCourt surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Mr. Tobin surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Ms. Piell surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Ms. Winkler surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Mr. Marcus surrendered shares to the company to fulfill tax withholding obligations upon the vesting of restricted stock on 3/15/2026.

Ms. Fitzpatrick surrendered shares to the company to fulfill tax withholding obligations upon the vesting of restricted stock on 3/15/2026.

Mr. Sammann surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Represents the vesting of performance shares granted in 2022 under CME Group's Omnibus Stock Plan. The number of shares was determined based on the company's achievement of total shareholder return relative to the S&P 500 measured over a three-year performance period from January 1, 2023 through December 31, 2025.

Mr. Cutinho surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.

Mr. Duffy surrendered shares to the company in order to fulfill tax withholding obligations related to the receipt of the performance share award.