News Release

Chicago Mercantile Exchange Holdings Inc. Distributes Letter to CBOT Shareholders

Mon Jun 25 2007

CHICAGO, June 25 /PRNewswire-FirstCall/ -- Chicago Mercantile Exchange Holdings Inc. (NYSE: CME)(NASDAQ: CME) today sent the following letter to shareholders and members of the Chicago Board of Trade (NYSE: BOT):

  June 25, 2007

  SETTING THE RECORD STRAIGHT ON THE CME/CBOT MERGER:
  KNOW THE RISKS OF DEALING WITH ICE

  Dear CBOT Shareholders:

We are sending this letter to set the record straight and make sure that all CBOT members and shareholders have the facts they need to see through the ICE propaganda and understand the significant risks of their proposal.

ICE Offers a Riskier Currency

The current ICE stock price is clearly being driven by a takeover premium, not by fundamentals. But don't just take our word for it. The financial community has issued a number of clear warnings about the risk of ICE's stock:

  Bank of Montreal:  "If it became evident ICE would win [CBOT], ICE stock
  would fall substantially."  - Mike Vinciquerra - 6/14/07

  Bank of America: "Takeout speculation has been fueling the stock of late,
  but we do not believe a takeout is likely near-term.  And while
  fundamentals have been decent, we are not sure they are strong enough to
  support the stock at current levels." - Chris Allen - 6/14/07

  Goldman Sachs: "The biggest risk to our price target is ICE's potential
  acquisition of BOT.  While the transaction would have attractive long term
  accretion, there are significant hurdles to completing the integration.
  Further, should NYMEX attract a larger share of commodity volumes or the
  global OTC market slow, earnings could underperform our expectations."  -
  Daniel Harris - 6/14/07

  CIBC: "We believe that ICE's stock has traded higher since the CME revised
  offer in expectation that ICE would not succeed in its bid attempt and
  would itself become a takeover target." - Niamh Alexander - 6/13/07

  Deutsche Bank:  "We believe ICE would have to raise its bid substantially
  to overcome CME's operational advantage, with DOJ approval, and that any
  new bid could pressure ICE shares to the downside."  - Rob Rutschow -
  6/13/07

  Credit Suisse:  "We believe the greatest near-term risk to our ICE call
  relates to its bid to merge with CBOT. We believe a successful bid would
  likely lead to sizeable equity issuance/earnings dilution, higher
  investment spending and integration risk while dampening ICE's stand-alone
  high growth franchise."  - Howard Chen - 6/11/07

  ICE Provides a High Risk Proposition

The facts are clear. ICE does not have the technology or clearing capabilities to manage CBOT business. To accommodate your trading activity, ICE Clear will have to increase its clearing capacity by thirteen times NYBOT's average daily transactions and nineteen times its peak transactions. To handle your electronic trading volume on its platform, ICE will have to increase its technology capacity by six times to handle an average CBOT day and ten times to handle your peak days. Again, you don't have to take our word for it.

  Richard Dennis, Independent Trader:  "When it comes to the reliability of
  trading platforms, the Merc is a nine, the Board of Trade is a six and ICE
  is a one," (Richard) Dennis told the Sun-Times. He said that of all the
  trading glitches he encounters, "80 percent of them are due to ICE and the
  rest equally to the Board of Trade and the Merc." - Chicago Sun-Times -
  6/21/07

  Computer Sciences Corporation, an independent technology consulting firm:
  "transferring to the ICE platform would create substantial risk to CBOT
  and its pools of liquidity." - CSC Report - May 2007

Keep in mind that ICE is still integrating NYBOT and NGX; it still needs to integrate ChemConnect; it stills needs to build new data centers; it still needs to build out NYBOT's clearing; it still needs to build a London clearing operation; and it just announced another merger with the Winnipeg Commodity Exchange.

ICE Wants to Minimize the Value of Your CBOE Exercise Rights

Through its proposal with CBOE, ICE has undervalued your exercise rights. Why have CBOE and ICE drastically undervalued the ERP, offering to buy out your ERPs for a fraction of their value? Do you really trust that ICE and CBOE will protect that value? In contrast, CME and CBOT have now provided a minimum value of $500,000 per ERP along with the upside to unlock the full value.

  Jerry Zordani, CBOT member:  "The Merc's latest offer is very compelling.
  It preserves the exercise rights." - Chicago Tribune - 6/15/2007

  CBOT/CME Merger is the Right Trade for CBOT Members and Shareholders

A CBOT/CME combination delivers real and immediate and long-term benefits for members, shareholders and customers. Together, we will be the industry's leading exchange with a powerful growth strategy. We will offer the most world's most diverse derivatives product line available via state of the art trading platform or floor. We will have world-class clearing that will continue to provide over $1 billion in margin efficiencies. We will continue our collective tradition of providing preferred pricing for high volume producers. We have regulatory clearance. And-we are ready to integrate today and can begin delivering value immediately.

As members and shareholders of CBOT Holdings you are sophisticated market participants. You understand risk. On July 9, the choice is clear: vote "YES" on a CBOT/CME combination.

  Sincerely,

  Terry Duffy

  Craig Donohue

  Forward-Looking Statements

This document may contain forward-looking information regarding Chicago Mercantile Exchange Holdings Inc. and CBOT Holdings, Inc. and the combined company after the completion of the merger that is intended to be covered by the safe harbor for "forward-looking statements" provided by the Private Securities Litigation Reform Act of 1995. These statements include, but are not limited to, the benefits of the business combination transaction involving CME and CBOT, including future financial and operating results, the new company's plans, objectives, expectations and intentions and other statements that are not historical facts. Such statements are based on current beliefs, expectations, forecasts and assumptions of CME and CBOT's management which are subject to risks and uncertainties which could cause actual outcomes and results to differ materially from these statements. Other risks and uncertainties relating to the proposed transaction include, but are not limited to the satisfaction of conditions to closing; including receipt of shareholder and member approvals; the proposed transaction may not be consummated on the proposed terms; uncertainty of the expected financial performance of CME following completion of the proposed transaction; CME may not be able to achieve the expected cost savings, synergies and other strategic benefits as a result of the proposed transaction; the integration of CBOT with CME's operations may not be successful or may be materially delayed or may be more costly or difficult than expected; general industry and market conditions; general domestic and international economic conditions; and governmental laws and regulations affecting domestic and foreign operations.

For more information regarding other related risks, see the Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q of CME and CBOT Holdings for their fiscal years ended December 31, 2006 and their quarters ended March 31, 2007. Said documents are available online at http://www.sec.gov/ or on request from CME or CBOT Holdings, respectively. You should not place undue reliance on forward-looking statements, which speak only as of the date of this document. Except for any obligation to disclose material information under the Federal securities laws, neither CME nor CBOT Holdings undertakes any obligation to release publicly any revisions to any forward-looking statements to reflect events or circumstances after the date of this document.

Chicago Mercantile Exchange Holdings Inc. (NYSE: CME)(NASDAQ: CME) became the first publicly traded U.S. financial exchange on Dec. 6, 2002. The company was added to the Russell 1000® Index on July 1, 2003, and to the S&P 500® Index on Aug. 10, 2006. It is the parent company of Chicago Mercantile Exchange Inc. (http://www.cme.com/), the world's largest and most diverse financial exchange. As an international marketplace, CME brings together buyers and sellers on the CME Globex® electronic trading platform and on its trading floors. CME offers futures and options on futures in these product areas: interest rates, stock indexes, foreign exchange, agricultural commodities, energy, and alternative investment products such as weather, real estate and economic derivatives. CME is a wholly owned subsidiary of Chicago Mercantile Exchange Holdings Inc. (NYSE: CME)(NASDAQ: CME).

Further information about Chicago Mercantile Exchange Holdings Inc. and Chicago Mercantile Exchange Inc. is available on the CME Web site at http://www.cme.com/.

CME-G

SOURCE: Chicago Mercantile Exchange Holdings Inc.

CONTACT: Media, Anita Liskey, +1-312-466-4613, or Pamela Plehn,
+1-312-930-3446, news@cme.com, or Investors, John Peschier, +1-312-930-8491,
all of Chicago Mercantile Exchange Holdings Inc.

Web site: http://www.cme.com/

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