CME GROUP INC.

Approval of an amendment to our certificate of incorporation to eliminate the right of the Class B-2 shareholders to elect two directors

Class B-2 Election Rights and effect of the Class B-2 Proposal Pursuant to our current certificate of incorporation, holders of shares of Class B-2 common stock, representing a total of 813 shares of Class B-2 common stock, par value $.01 per share, have the right to elect two Class B-2 directors. Additionally, pursuant to our current bylaws, the director nominations included in our proxy statement mailed to shareholders in conjunction with our annual meeting of shareholders shall include any nominee for a Class B-2 Director who is nominated by the holders of at least 100 shares of Class B-2 common stock (the Class B-2 Nominating Rights). The board of directors has approved, adopted and declared advisable the amendment to our certificate of incorporation as set forth in its entirety in Appendix D with deletions indicated by strikeouts and additions indicated by underlining. We refer to this amendment as the Class B-2 Amendment. The Class B-2 Amendment provides for the elimination of the Class B-2 Election Rights in their entirety beginning at our 2027 annual meeting. We encourage shareholders to review the full text of the Class B-2 Amendment. The general description of the Class B-2 Amendment set forth herein is qualified in its entirety by reference to the full text of Appendix D. As described on page 117, other than the impact to the rights to elect the Class B-2 Directors, the approval of the Class B-2 Proposal will not have any impact on shares of Class B-2 common stock. The Class B-2 Proposal does not have any impact on trading membership as described on page 118. To implement the Class B-2 Proposal, in the event the Class B-2 Proposal is approved and upon the effectiveness of the Class B-2 Amendment, the board of directors will adopt the amendment and restatement of our current bylaws as set forth in New Bylaws with deletions indicated by strikeouts and additions indicated by underlining. If the Class B-2 Proposal is approved, the New Bylaws will implement the elimination of all Class B-2 Election Rights and Class B-2 Nominating Rights. The New Bylaws also contain footnotes to indicate which changes will be made if only the Class B-2 Proposal is approved, if all of the Class B Election Rights Proposals are approved or if only certain of the Class B Election Rights Proposals are approved. The general description of the New Bylaws set forth herein is qualified in its entirety by reference to the full text of Appendix G.

BOARD RECOMMENDATION

Our board of directors has approved, adopted and declared advisable the Class B-2 Proposal and recommends that you vote “FOR” the Class B-2 Proposal. A vote “FOR” the Class B-2 Proposal is a vote in favor of adopting the Class B-2 Amendment.

For more information, please refer to Introduction to ITEMS Four, Five, Six and Seven, beginning on page 53.