For example,
If there is an abnormal volume upon a particular downbar after a prolonged downtrend and the range of that bar is pretty wide when compared to earlier bars, you suspect it to be a selling climax. So volume is giving you an important clue as what is going to happen next. If it is indeed a selling climax, then there is not much downside left. You will be looking for the actual bottoming of the stock. You will look for evidence that downtrend has indeed ended. What could this evidence be? Repeated tests of that low which ends in failure. Final confirmation comes when the price reverses its trend (downtrend), forms a base and threafter begins uptrend.
I have just given you a 100 crore rupees worth tip.
Should I add more confusion? Try to lookout all downbars with heavy volume and wide range. Lookout where they happened and why they happened. Lookout what happened thereafter. I never said that trading is easy.