Exhibit 16

Office of the Chief Accountant
Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, DC 20549

May 17, 2002

Dear Sir or Madam,

We have read Item 4 included in the Current Report on Form 8-K dated May
15, 2002 of Chicago Mercantile Exchange Holdings Inc. to be filed with the
Securities and Exchange Commission and are in agreement with the statements
contained therein.

Very truly yours,





Arthur Andersen LLP

MC

Copy to:
Mr. David G. Gomach
Chief Financial Officer
Chicago Mercantile Exchange Holdings Inc.