Margins for the first month of the NYISO Zone A off-peak electricity futures contract will decrease to $5,000 from $6,000 for clearing members, to $5,500 from $6,600 for members, and to $6,750 from $8,100 for customers. The margins for the second to sixth months will remain the same. Margins for the seventh to 11^th months will decrease to $3,000 from $4,500 for clearing members, to $3,300 from $4,950 for members, and to $4,050 from $6,075 for customers. The margins for all other months will remain unchanged.

Margins for the first month of the NYISO Zone G off-peak electricity futures contract will decrease to $5,000 from $6,000 for clearing members, to $5,500 from $6,600 for members, and to $6,750 from $8,100 for customers. The margins for the second to sixth months will remain the same. Margins for the seventh to 11^th months will decrease to $3,000 from $4,500 for clearing members, to $3,300 from $4,950 for members, and to $4,050 from $6,075 for customers. The margins for all other months will increase to $3,000 from $2,500 for clearing members, to $3,300 from $2,750 for members, and to $4,050 from $3,375 for customers.

Margins for the first month of the NYISO Zone J off-peak electricity futures contract will decrease to $5,000 from $6,000 for clearing members, to $5,500 from $6,600 for members, and to $6,750 from $8,100 for customers. The margins for the second to sixth months will decrease to 3,000 from $5,000 for clearing members, to $3,300 from $5,500 for members, and to $4,050 from $6,750 for customers. Margins for the seventh to 11^th months will decrease to $3,000 from $4,500 for clearing members, to $3,300 from $4,950 for members, and to $4,050 from $6,075 for customers. The margins for all other months will remain unchanged.

Margins for the first month of the ISO New England Internal Hub peak electricity futures contract will decrease to $8,000 from $8,500 for clearing members, to $8,800 from $9,350 for members, and to $10,800 from $11,475 for customers. The margins for the second to sixth months will decrease to $7,000 from $7,500 for clearing members, to $7,700 from $8,250 for members, and to $9,450 from $10,125 for customers. Margins for the seventh to 11^th months will decrease to $4,000 from $4,500 for clearing members, to $4,400 from $4,950 for members, and to $5,400 from $6,075 for customers. The margins for all other months will decrease to $3,000 from $3,500 for clearing members, to $3,300 from $3,850 for members, and to $4,050 from $4,725 for customers.

Margins for the first month of the Northern Illinois Hub off-peak electricity futures contract will remain the same. The margins for the second to sixth months will decrease to $1,500 from $2,500 for clearing members, to $1,650 from $2,750 for members, and to $2,025 from $3,375 for customers. Margins for the seventh to 11^th months will decrease to $1,500 from $2,000 for clearing members, to $1,650 from $2,200 for members, and to $2,025 from $2,700 for customers. The margins for all other months will remain the same.

Margins for the first month of the AEP-Dayton Hub off-peak electricity futures contract will remain the same. The margins for the second to sixth months will decrease to $1,500 from $2,500 for clearing members, to $1,650 from $2,750 for members, and to $2,025 from $3,375 for customers. Margins for the seventh to 11^th months will decrease to $1,500 from $2,000 for clearing members, to $1,650 from $2,200 for members, and to $2,025 from $2,700 for customers. The margins for all other months will decrease to $1,500 from $2,500 for clearing members, to $1,650 from $2,750 for members, and to $2,025 from $3,375 for customers.

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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: Brenda Guzman 212-299-2436 or  Keil Decker, 212-299-2209

Forward Looking and Cautionary Statements