what triggered the price rise. as steve kroft reported in 2009, many people believe it had more to do with wall street speculation than with oil companies. >> to understand what happened to the price of oil, you first have to understand the way it's traded. for years, it's been bought and sold on something called the commodities futures market. here at the new york mercantile exchange, it's traded alongside cotton and coffee, copper and steel by brokers who buy and sell contracts to deliver those goods at a certain price at some date in the future. it was created so that farmers could gauge what their unharvested crops would be worth months in advance, so that factories could lock in the best price for raw materials and airlines could manage their fuel costs. but in late 2007, that market started to behave erratically. and when oil doubled to more than $147 a barrel, no one was more suspicious