What is the main purpose of this 8-K filing?

The primary purpose of this 8-K filing is to report key developments related to CME Group's proposed merger with GFI Group, including the delivery of a financial fairness opinion and the filing of tax opinions and supplemental merger documents with the SEC.

What is the significance of the fairness opinion from Greenhill & Co., LLC?

The fairness opinion from Greenhill & Co., LLC indicates that, from a financial perspective, the proposed merger consideration offered to GFI Group common stockholders is fair. This is a common step in mergers and acquisitions to provide assurance to shareholders.

What is the tax implication of the merger as stated in the filing?

According to tax opinions from Skadden, Arps, Slate, Meagher & Flom LLP and White & Case LLP, the merger is expected to qualify as a reorganization under Section 368(a) of the Internal Revenue Code. This generally means that for U.S. federal income tax purposes, neither CME Group nor GFI Group (nor their respective stockholders, in most cases) will recognize gain or loss on the transaction.

What action do GFI Group shareholders need to take?

GFI Group shareholders are being asked to vote on the proposed merger. They will receive proxy materials, including a proxy statement/prospectus supplement, and will use the provided proxy card (Exhibit 99.2) to cast their votes for or against the merger at a special meeting.

CME 8-K SEC Disclosure — Jan 26, 2015

Summary

This Form 8-K filing by CME Group Inc. (CME) on January 26, 2015, primarily relates to the ongoing merger with GFI Group Inc. (GFI Group). The key information for investors centers around the financial fairness opinion received from Greenhill & Co., LLC regarding the merger consideration for GFI Group stockholders. This opinion, delivered on January 20, 2015, and subsequently confirmed in writing, suggests that the proposed terms are financially fair from the perspective of GFI Group's shareholders. Furthermore, the filing details the submission of a supplemental document to the SEC on January 23, 2015, which amends the previously filed proxy statement/prospectus for the merger. This supplement, along with the original proxy materials, will be used to solicit GFI Group shareholder votes on the merger. The report also includes crucial tax opinions from Skadden, Arps, Slate, Meagher & Flom LLP and White & Case LLP, both confirming that the merger is expected to qualify as a reorganization under Section 368(a) of the Internal Revenue Code.

Key Highlights

1CME Group has received a written fairness opinion from Greenhill & Co., LLC, dated January 20, 2015, stating the merger consideration for GFI Group common stock holders is fair from a financial point of view.
2A supplement to the proxy statement/prospectus for the GFI Group merger was filed with the SEC on January 23, 2015.
3Both CME Group and GFI Group have received tax opinions from Skadden, Arps, Slate, Meagher & Flom LLP and White & Case LLP, confirming the merger will likely qualify as a tax-free reorganization under Section 368(a) of the Internal Revenue Code.
4The filing includes the consent of Greenhill & Co., LLC (Exhibit 99.1) and the proxy card for GFI Group stockholders (Exhibit 99.2) for voting on the merger.
5The merger is being presented to GFI Group stockholders for their approval at a special meeting.
6The SEC declared the Form S-4 registration statement for the merger effective on December 24, 2014.

CME GROUP INC. 8-K Report, Corporate Update (Jan 26, 2015)

Summary

Key Highlights

Frequently Asked Questions