Internet debut exuberance may still be the order of the day, as Yandex (NASDAQ:YNDX) - the "Google (NASDAQ:GOOG) of Russia" - opens at $35, up 40% from its $25 offer price. It's the world's biggest tech IPO this year; China's social network Renren (NYSE:RENN) popped 29% on its first day (down 28.9% since), and LinkedIn (LNKD) is still around double its debut price.