News Release

Exchange to Change Margins for Copper Futures Contracts

Tue May 23 2006

NEW YORK, N.Y., May 23, 2006 — The New York Mercantile Exchange, Inc. today announced margin changes for its copper futures contracts, effective as of the close of business tomorrow.

Margins for the May 2006 to December 2006 copper futures contracts will increase to $7,050 from $6,500 for clearing and non-clearing members and to $10,125 from $8,775 for customers.

Margins for all other months will increase to $6,000 from $5,000 for clearing and non-clearing members and to $8,100 from $6,750 for customers.

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Forward Looking and Cautionary Statements
This press release may contain forward–looking statements within the meaning of the Private Securities Litigation Reform Act, with respect to our future performance, operating results, strategy, and other future events. Such statements generally include words such as could, can, anticipate, believe, expect, seek, pursue, and similar words and terms, in connection with any discussion of future results. Forward–looking statements involve a number of assumptions, risks, and uncertainties, any of which may cause actual results to differ materially from the anticipated, estimated, or projected results referenced in forward–looking statements. In particular, the forward–looking statements of NYMEX Holdings, Inc., and its subsidiaries are subject to the following risks and uncertainties: the success and timing of new futures contracts and products; changes in political, economic, or industry conditions; the unfavorable resolution of material legal proceedings; the impact and timing of technological changes and the adequacy of intellectual property protection; the impact of legislative and regulatory actions, including without limitation, actions by the Commodity Futures Trading Commission; and terrorist activities and international hostilities, which may affect the general economy as well as oil and other commodity markets. We assume no obligation to update or supplement our forward–looking statements.

Contact: Anu Ahluwalia , 299-2439

Corporate Communications

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