EX-4.1






EXHIBIT 4.1




SECOND AMENDMENT TO RIGHTS AGREEMENT




This Second Amendment to Rights Agreement (this “Amendment”), dated as of October 26, 2005 is
by and between Chicago Mercantile Exchange Holdings Inc., a Delaware corporation (the “Company”),
and Computershare Investor Services, LLC, a Delaware limited liability company (“Computershare”).



W I T N E S S E T H




WHEREAS, the Company previously entered into a Rights Agreement, dated as of November
30, 2001 and amended as of November 13, 2002 (the “Rights Agreement”), with Computershare (as
successor to Mellon Investor Services LLC) as Rights Agent (the “Rights Agent”);



WHEREAS, pursuant to Section 27 of the Rights Agreement, the Company and
Computershare may supplement or amend the Rights Agreement from time to time in accordance with the
provisions of Section 27 thereof; and



WHEREAS, the Board of Directors of the Company has determined that an amendment to the Rights
Agreement as set forth herein is in the best interest of the Company and its stockholders, and the
Company and Computershare desire to evidence such amendment in writing.



NOW, THEREFORE, in consideration of the premises and the mutual agreements herein set
forth, the parties hereby agree as follows:



Section 1. Amendment of Rights Agreement. Paragraph (b) of Section 7 of the Rights
Agreement is amended by deleting such paragraph (b) in its entirety and substituting a new
paragraph (b) to read as follows:



(b) The Purchase Price for each one one-thousandth of a share of Preferred Stock pursuant
to the exercise of a Right shall be $1,000, and shall be subject to adjustment from time to time as
provided in Sections 11 and 13(a) hereof and shall be payable in accordance with paragraph (c)
below.



Section 2. Continued Effectiveness. The parties hereto hereby acknowledge and agree that,
except as specifically amended hereby, the Rights Agreement shall remain in full force and effect
in accordance with its terms.



Section 3. Governing Law. This Amendment shall be deemed to be a contract made under the
laws of the State of Delaware and for all purposes shall be governed by and construed in accordance
with the laws of such State applicable to contracts made and to be performed entirely within such
State.



Section 4. Execution in Counterparts. This Amendment may be executed in any number of
counterparts and each of such counterparts shall for all purposes be deemed to be an original, and
all such counterparts shall together constitute one and the same instrument.



Section 5. Defined Terms. Except as otherwise expressly provided herein, or unless the
context otherwise requires, all capitalized terms used herein have the meanings assigned to them in
the Rights Agreement.



[SIGNATURE PAGE FOLLOWS]

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 IN WITNESS WHEREOF, the parties hereto have
caused this Amendment to be duly executed and effective as of the day and year above written.




CHICAGO MERCANTILE EXCHANGE HOLDINGS INC.




By: /s/ Kathleen M. Cronin

Name: Kathleen M. Cronin

Title: Managing Director, General Counsel and

Corporate Secretary





COMPUTERSHARE INVESTOR SERVICES, LLC




By:/s/ Keith Bradley

Name: Keith Bradley

Title: Vice President





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