Sigmatrader is a simulated stock exchange that allows users to make real profit with no risk. All of our revenue comes from Google Adsense which is used to compensate our players for their winnings. If you reach $10 in profits on Sigmatrader we will send you a check. We will even give you $100 to get started trading for free. Best, The Sigmatrader Team - http://sigmatrader.com