There's a lot of arguments for and against charting, and...

There's a lot of arguments for and against charting, and sometimes I'm a sceptic as well. What charts can do is give you a guide as to whether a stock is in an up trend or a down trend. Charts can help predict where resistance or support points may be, but sometimes a stock will do what it wants without your permission and regardless of what any chart says, regardless of what you pay for a chart package.
What is obvious is that many people use charting as a mechanical tool to give entry and exit points. The more you learn the more you can see entries and exits being made purely with influences on charts. Your classic would be a price of a stock that cannot go above a certain price. Many would be eyeing off stocks caught on resistance and will pounce on the breakout. The fact you see big volumes on breakout gives support to charting theories. The more people use them the more the effects will be realised.

Also, when a stock is in a downtrend many chartists will not consider making an entry until the long term down trend line is broken. On breakout they may wait several days or weeks until a new uptrend line is made. Usually once the the price bars touch the uptrend line will they consider entering.