US futures regulator CFTC probing speed traders

WASHINGTON (REUTERS) - The US Commodity Futures Trading Commission is investigating high-frequency traders to see if they were breaching the derivatives regulator's rules, its chief said on Thursday.

"Staff (is) responding to concerns brought to us about certain practices, whether it be spoofing just to give one example, whether that's running afoul of our rule," Acting Chairman Mark Wetjen told reporters during a meeting.

"And then whether or not it meets the definition of manipulative activity under our statute," he said.

Many banks and hedge funds use sophisticated computer programs to send large batches of orders into equity and futures markets in fractions of a second, a controversial practice known as high-frequency trading (HFT).

Proponents of HFT say the firms make it easier for other buyers and sellers to meet each other in the market, but critics argue it can cause sudden market crashes and easily mask market manipulation or other illegal activity.

Spoofing is the practice of rapidly sending out large numbers of orders, which are then quickly withdrawn to give the illusion of a hot market and attract others.

Wetjen said agency staff, including people in the enforcement division, were looking at the activity.