NGX Canadian Natural Gas IndexTM is a commodity index based on natural gas as traded on NGX. This Canadian dollar denominated index tracks the performance of Alberta's "One-month spot" physical market price. The index is an Excess Return index where the return reflects an investment rolling from month to month and not any Collateral Return. The initial benchmark value of the index was set at 1000 as of December 19, 2007. The index is calculated on a daily basis as of 2:30PM ET (12:30PM MT).