Question, are the charts simply random charts from random companies recently trading? Where are they coming from? I see AOL is providing them, but how are they

Question, are the charts simply random charts from random companies recently trading? Where are they coming from? I see AOL is providing them, but how are they selected for use in the site? This might explain the amount of users who seem to be succeeding by clicking only the "buy" button. Is there an algorithm that makes sure the gains and losses are evenly distributed in the charts (less realistic), or are the charts completely random (mimicking the experience a real stock trader would be presented with the charts)?