"Futures" is a term used to designate contracts covering the sale of financial instruments or physical commodities for future delivery on a commodity exchange. The asset underlying the futures contract (the thing to be bought or sold) can be just about anything, but is most commonly a physical commodity (as in pork bellies or oil futures) or another financial instrument (as in stock futures). Owners of underlying commodities can use futures to hedge against the uncertainty of future market prices--they can lock in a sale price--while investors can speculate on the changes in the market price of the underlying asset.