February 9, 2016 - The court denied defendants' motion to dismiss.
September 9, 2015 - Defendants filed a motion to dismiss.

July 8, 2015 - The lead plaintiff filed a second amended complaint.

May 15, 2015 - The lead plaintiff filed an amended complaint.

February 20, 2015 - Lead plaintiff and lead counsel were appointed.

January 27, 2015 - Lead plaintiff motion was filed.

November 26, 2014 - An investor, who sold shares of GFI Group Inc (NYSE: GFIG) between July 30, 2014 and September 8, 2014, filed a lawsuit in the U.S. District Court for the Southern District of New York over alleged violations of Federal Securities Laws by GFI Group Inc (NYSE: GFIG) in connection with the proposed acquisition of GFI Group Inc.

On July 30, 2014, CME Group and GFI Group Inc announced CME Group will acquire all of the outstanding shares of GFI Group Inc in exchange for $4.55 per share in CME Group Class A Common Stock.

According to the complaint the plaintiff alleges on behalf of sellers of GFI Group Inc (NYSE: GFIG) common shares between July 30, 2014 and September 8, 2014, that the defendants violated Federal Securities Laws by issuing allegedly material misrepresentations and failing to disclose to investors material facts indicating that GFI Group Inc had received superior offers and inquiries from third party purchasers interested in acquiring GFI Group Inc.

More specifically, the plaintiff claims that defendants between July 30, 2014 and September 8, 2014 made allegedly false and/or misleading statements and/or failed to disclose that prior to announcing the proposed acquisition with CME Group, GFI Group Inc had received superior offers and/or inquiries from other interested third parties, including BGC Partners, Inc.; and that the CME Group offer did not optimize GFI Group Inc 's value for stockholders and did not represent a singular and unique opportunity to return value. Defendants withheld this material, nonpublic information from, and otherwise misled investors, so that defendants could pursue and personally profit from a sweetheart deal with CME Group.

On September 15, 2014 GFI Group Inc confirmed that it received an unsolicited proposal from BGC Partners, Inc. to acquire all the shares of common stock of GFI Group Inc (NYSE: GFIG) for $5.25 per share in cash.

On November 4, 2014 GFI Group Inc announced that its board of directors, other than Messrs. Gooch and Heffron, both of whom abstained, determined to reject the unsolicited tender offer from BGC Partners, Inc. to acquire all of the outstanding shares of common stock of GFI Group Inc for $5.25 per share in cash.

Then on December 2, 2014 CME Group Inc and GFI Group Inc announced that they have revised their agreements to increase the consideration payable to GFI Group Inc stockholders from $4.55 per share in CME Group stock to $5.25 per share, payable in a mix of shares of CME Group Class A common stock and cash. GFI Group Inc also said that Jersey Partners Inc., GFI Group Inc's largest stockholder, and the members of the GFI Group Inc Management Consortium and their respective affiliates (other than GFI Group Inc) continue to agree to vote all of their GFI Group Inc shares in favor of the transaction at the GFI Group Inc stockholder meeting to approve the transaction.

Shares of GFI Group Inc (NYSE: GFIG) grew on December 11, 2014, to as high as $5.55 per share.