A SPREAD in the energy market reflecting the price differential between crude oil and a refined product, generally gasoline or heating oil; the spread can be traded through a single FUTURE or OPTION contract on certain EXCHANGES. A hedger or speculator can buy the crack spread (e.g., purchase crude and sell heating oil or gas) to take advantage of positive margins in refining, and sell the spread (e.g., sell crude and purchase heating oil or gas) to profit from negative margins. See also SPARK SPREAD.