From The Washington Post

Regulators had long classified a private Swiss energy conglomerate called Vitol as a trader that primarily helped industrial firms that needed oil to run their businesses.

But when the Commodity Futures Trading Commission examined Vitol's books last month, it found that the firm was in fact more of a speculator, holding oil contracts as a profit-making investment rather than a means of lining up the actual delivery of fuel. Even more surprising to the commodities markets was the massive size of Vitol's portfolio -- at one point in July, the firm held 11 percent of all the oil contracts on the regulated New York Mercantile Exchange.

The discovery revealed how an individual financial player had gained enormous sway over the oil market without the knowledge of regulators. Other CFTC data showed that a significant amount of trading activity was concentrated in the hands of just a few speculators.

The CFTC, which learned about the nature of Vitol's activities only after making an unusual request for data from the firm, now reports that financial firms speculating for their clients or for themselves account for about 81 percent of the oil contracts on NYMEX, a far bigger share than had previously been stated by the agency. That figure may rise in coming weeks as the CFTC checks the status of other big traders. ...

CFTC documents show Vitol was one of the most active traders of oil on NYMEX as prices reached record levels. By June 6, for instance, Vitol had acquired a huge holding in oil contracts, betting prices would rise. The contracts were equal to 57.7 million barrels of oil -- about three times the amount the United States consumes daily. ...

Using swap dealers as middlemen, investment funds have poured into the commodity markets, raising their holdings to $260 billion this year from $13 billion in 2003. During that same period, the price of crude oil rose unabated every year.

CFTC data show that at the end of July, just four swap dealers held one-third of all NYMEX oil contracts that bet prices would increase. Dealers make trades that forecast prices will either rise or fall. Energy analysts say these data are evidence of the concentration of power in the markets. ...