Midday Report: Chipotle Faces New Investigation; U.S. Stocks Sell Off

Stocks remained in the red by the middle of the session, though off the day's lows. Fears over North Korea's hydrogen bomb tests and continued concerns over the Chinese economy kept markets under pressure. Crude oil traded at 11-year lows after domestic inventories fell at a slower-than-expected pace in the past week. Recent strength in U.S. services activity dissipated in December as the sector grew at its slowest pace in nearly a year. Service providers pointed to uncertainty over the economic outlook and weaker confidence among consumers. Chipotle (CMG) tumbled after it issued fourth-quarter profit and sales guidance well below estimates as it faces the fallout of an E.coli outbreak. The burrito chain also said it had received a subpoena from a federal grand jury in California. TheStreet's Keris Lahiff reports from Wall Street.