"After oil prices surged past $100 a barrel in 2008, suspicions that traders had manipulated the market led to Congressional hearings and regulatory investigations. But they produced no solid cases in the record run-up in gasoline prices.
But on Tuesday, federal commodities regulators filed a civil lawsuit against two obscure traders in Australia and California and three American and international firms.
The suit says that in early 2008 they tried to hoard nearly two-thirds of the available supply of a crucial American market for crude oil, then abruptly dumped it and improperly pocketed $50 million.
The regulators from the Commodity Futures Trading Commission would not say whether the agency was conducting any other investigations into oil speculation. With oil prices climbing again this year, President Obama has asked Attorney General Eric H. Holder Jr. to set up a working group to look into fraud in oil and gas markets and 'safeguard against unlawful consumer harm.'"