November 19, 2012 (Chinavestor) China's mighty Sina Copr. (NASDAQ:SINA) reported third quarter numbers and issued Q4 guidance on Friday, sending its stock to a tail spin. While the stock may make a come back on Monday, it might just be a dead cat bounce. There are serious fundamental challenges Sina Corp. (NASDAQ:SINA) has to overcome to restore investors' confidence. And it's not just Sina that's suffering. NetEase.com Inc. (NASDAQ:NTES) as well as Baidu.com Inc. (NASDAQ:BIDU) suffered severe blows last week.