Filed by Chicago Mercantile Exchange Holdings Inc. pursuant

to Rule 425 under the Securities Act of 1933, as amended, and

deemed filed pursuant to Rule 14a-6 under the

Securities Exchange Act of 1934, as amended.

Subject Company: CBOT Holdings, Inc.

Subject Company’s Commission File No.:001-32650

On July 9, 2007, Chicago Mercantile Exchange Holdings Inc. ran the following advertisement in Chicago newspapers.

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