Zynga up 16.8% After Facebook Files for IPO

The shares of Zynga Inc (NASDAQ:

) are trading at all-time highs intraday following Facebook's IPO filing. Facebook filed the form S-1 for a five billion dollar IPO last night. Zynga develops social games mainly for the Facebook platform. The company went public in December and its most well-know game titles are Farmville and Mafia Wars. Zynga is currently trading at $12.38, a gain of $1.78 or 16.79%.