Amazon (AMZN) gains ahead on Black Friday, ahead of Cyber Monday

Amazon.com (NASDAQ: AMZN) shares nosed up 1.8% to $339.54. The online book seller is counting on big demand Friday through Cyber Monday, but the e-commerce giant is facing a new challenge from Wal-Mart in mobile shopping. Share volume was 1.3 million, compared to an all-day average of 3.8 million