It would seem that the normal laws of supply and demand would be the foundation for establishing the current market price for commodities like crude; and to some extent this is the case. However, when speculative interests are taken into account, the picture becomes fuzzy. While millions of barrels of crude oil are bought and sold each day, consumers and producers look to hedge the risk of a change in price for the raw material before they make the purchase.
Full article at: Crude trading