Wall St. falls on U.S. growth concern; Shake Shack, Amazon rally

U.S. stocks fell on Friday, pressured by concern over by domestic economic growth and the potential impact of euro zone instability on U.S. corporate results. U.S. economic growth slowed sharply in the fourth quarter as weak business spending and a wider trade deficit offset the fastest pace of consumer spending since 2006. "It's just a little disheartening to see the U.S. didn't have such a great quarter and it puts a little bit of fear in the minds of the people," said Jose