What is the VIX?
http://www.investopedia.com/terms/v/vix.asp
See the article in post #2 for a complete defination:
"The Volatility Index (Chicago Options: ^VIX), also called VIX or fear index, measures how concerned options traders are that prices will drop. As with all sentiment indicators, the value of the VIX lies in its contrarian application. For the first time since August 2008, the VIX has now dropped below 20; a reading that has foreshadowed trouble in the past."