After the CFTC issued 16 of those letters, speculation grew to more than 80 percent of the activity on the commodity exchanges, a Congressional staffer told Taibbi.

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This is the benchmark gasoline product traded on the major commodity exchanges.

FORBES: Commodities Turn the Corner

Reg NMS does not cover commodity exchanges, which allows the member-owned, floor-trading New York Mercantile Exchange to sustain its old ways although competition from the all-electronic IntercontinentalExchange could also force it to change.

ECONOMIST: Good times rarely last

In a statement Thursday evening, the Securities and Exchange Commission and Commodity Futures Trading Commission said they are working with other regulators and the exchanges to review unusual trading activity during the afternoon.

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Already, lots of energy and commodity exchanges are trying to get into the act.

ECONOMIST: Emissions

For the last three years, copper has traded on commodity exchanges in a narrow band centering around 76 cents per pound.

FORBES: Magazine Article

Experts on London's commodity exchanges claim that so much Russian nickel, aluminum and copper is being dumped on the market that world prices are depressed.

CENTERFORSECURITYPOLICY: Center For Security Policy