There are more theories on what works in stock investing than there are listed stocks. Each one seems to be successful at some point in time. However, there is still no single universally applicable formula. I am still in search of that magic formula. If any of you do find one, please post it in the comments section.
But if there can be said to be two warring camps on the right approach to stock investing, these are usually fundamental analysis and technical analysis. Both have loyal camps of followers who swear that their method works best.