Market price indexes are the backbone of the US energyindustry. They are widely used in bilateral natural gas and electric commoditymarkets to track spot andforward prices. In addition, indexes are used in a variety of other ways, includingas a price term reference in contracts, for settling imbalances or determiningpenalties in many gas pipeline tariffs, and as benchmarks when a state’spublic utility commission is reviewing the prudence of gas or electricity purchases.

Daily and monthly price