SecProbe.io

June 27, 2007
VIA FACSIMILE 312.407.8522

Rodd Schreiber, Esq.
Susan Hassan, Esq.
Skadden, Arps, Slate, Meagher & Flom LLP
333 West Wacker Drive
Chicago, IL 60606

Re:   Form 425 filings made on June 22 and 25, 2007
 Filed by Chicago Mercantile Exchange Holdings, Inc.
 File No. 001-32650 (Film Nos. 07939499, 07937025)

Ladies and Gentlemen:

We have reviewed your filings and have th e following comments.  If you disagree with
one or more of our comments, we will consider  your explanation as to why a comment may be
inapplicable or a revision unnecessary.  Please be as detailed as necessary in your explanation.
In some of our comments, we may ask CME to provide us with supplemental information so we may better understand your disclosure.  After re viewing this information, we may or may not
raise additional comments.

 Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure requir ements and to enhance the overall disclosure in
your filings.  We look forward to working with  you in these respects.  We welcome any
questions you may have about our comments or any other aspect of our review.  Feel free to call
us at the telephone number listed  at the end of this letter.

General
1. The note contained in the slid e pertaining to the implied ICE stock price references a
CME implied price that has not been included on  the slide.  Please advise us whether this
graph inadvertently omitted to state the CME implied price.  In addition, please briefly
explain to us why this graph s upports the belief that ICE’s st ock price is no longer driven
by the fundamentals.  Please confirm that futu re such presentations will emphasize that
such illustrations represent the beliefs of CME or will disclose why such observations and findings should be accepted as fact.
2. Each statement or assertion of opinion or beli ef expressed in additi onal soliciting material
must be characterized as such and be supported on a reasonable factual basis that is self-
evident, disclosed in the soliciting material s, or provided to the staff on a supplemental
basis.  We cite the following non-exhaustiv e examples of assertions that should be
specifically supported or not used in  future written communications:

Chicago Mercantile Exchange Holdings, Inc.
SEC Comment Letter dated June 27, 2007
Page 2
 On June 22, 2007:
• We have a long-standing pricing strategy of  providing the lowest trading fees for
member liquidity providers, with discounts that significantly exceed anything offered by ICE.
On June 25, 2007, the following statements made concerning the ICE proposal:

• Speculative synergy projections;

• Value of ICE stock not trading on fundamentals;

• Catastrophic integration risk; and

• Questionable clearing and technology.

* * * * *

Closing Comments

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filings reviewed by the staff to be certain that they have provided all information investors
require for an informed voting and investment decision.  Since the partic ipants are in possession
of all facts relating to their disc losure, they are responsible for the accuracy and adequacy of the
disclosures they have made.

In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the sta ff of the Division of Corporati on Finance in our review of your
filings or in response to our comments on your filings.

Please furnish a cover letter with your amendment that ke ys your responses to our
comments and provides any requested supplemental information.  Detailed cover letters greatly
facilitate our review.  Please  electronically file your cove r letter on EDGAR.  Again, please
understand that we may have additional comments after reviewing any amen dments or responses
to our comments.  If you have any ques tions, please contact me at 202.551.3266.

Sincerely,   Nicholas P. Panos
        S p e c i a l  C o u n s e l
        Office of Mergers & Acquisitions