Wall Street rallies as cold snap fires up crude oil

The S&P 500 and the Nasdaq rallied nearly 2 percent on Friday morning as a cold wave in the United States and Europe helped crude oil surge for a second day. All 10 major S&P sectors were in the black, led by a 4.67 percent jump in energy stocks. The Nasdaq soared more than 2 percent and was on track for its best day since Oct. 23.