U.S. stocks ended near session lows as Wall Street suffered a market-wide selloff on Friday. Tech stocks were among the worst performers after poor earnings from LinkedIn (LNKD) sent shares crashing. Biotech stocks were also sharply lower, weighing heavily on the Nasdaq. Crude oil suffered a tough end to the week, too, falling more than 2% to close below $31 a barrel. Oil has fallen 8% since Monday, its first weekly loss in three weeks. Netflix (NFLX) slumped after MoffettNathanson turned bearish, reducing its price target by $13 a share. Analysts said its market performance last year made for an overpriced valuation. Twitter (TWTR) also sold off on an analyst call. MKM Partners warned investors that the social network has 'shaky fundamentals.' TheStreet's Keris Lahiff reports from Wall Street.