As in other areas of the commodity market, energy pricese tend to track each other, trending up or down as a group. One of the biggest actively traded energy contracts aside from crude oil is natural gas.

Historically, a barrel of crude has been about seven times more expensive than the price for a BTU of natural gas, said Stephen Schork, a day trader who also is president at the Schork Report, an industry newsletter.

When that ratio gets way out of line, as it is now, he said that "either crude is too expensive, natural gas is too cheap, or both."