LinkedIn shares dive on weak forecast

LinkedIn shares plunged more than 40 percent on Friday after a weak outlook from the career-focused social network fueled fears of a slowdown. LinkedIn reported a loss of $166 million for 2015, far wider than the $16 million deficit for 2014. The outlook "implies material deceleration in growth, which removes support for the company's historically premium valuation," said Mark Mahaney at RBC Capital Markets in a research note.