Are speculative traders responsible for pushing up crude oil prices? Many, particularly in US congress, are arguing that they are. But traders and others who follow the markets tend to disagree, usually pointing out that the commodity futures markets, unlike cash stock markets, are not trading in a finite number of items, but are merely trading contracts that are eventually settled based on physical supply and demand.

The CFTC recently began publishing weekly figures that shed some more light on who is doing what in the sometimes opaque energy commodity markets, by breaking up categories of traders into four categories according to their involvement with the physical or financial sides of markets.  Market participants and commentators interpreted the data in a variety of ways: Barclays Capital, for example, said it indicated speculative traders (as opposed to those who deal in physical oil) were not unduly influencing prices; while others were less convinced that the new categories revealed anything of value at all.

Another set of figures published by the CFTC, published only quarterly, reveals the net positions of index investors - which includes index funds, swap dealers, pension funds, hedge funds and mutual funds. This data, according to Philip Verleger, energy analyst and economist, underlines the lack of influence that these investors have on energy prices.