To me the charts always seem to be trailing indica

To me the charts always seem to be trailing indicators. At least whenever I look at barcharts.com occasionally, I find it rates the stock as a buy AFTER it has gone up some amount, and then starts rating it as a sell after it has fallen some amount from the peak. If the charts were forward indicators we would all be rich! (or at least the traders would be as I know most of us don't trade the stock).