People who read this blog will know that I focus solely on price rather than fundamentals. However I also know that people are successful focusing on fundamentals.
The reason for my own preference is that there are many catalysts for movement in price, whether it be earnings or other press releases, other fundamental considerations, the state of the general market, whether there are supposed chart patterns that can be identified on that stock's chart, buying and selling of investors, swing traders, day traders or scalpers, market sentiment and so on.
At the end of the day no-one can know ALL the factors that make a stock's price go up and down. HOWEVER, there is one metric that gives you the sum total of all these factors, at that point in time - and that is the price. Therefore, it makes perfect sense to me to focus solely on that. After all, if I am long the only way I will make a profit is if the price goes up, and if I am short I will only make money if the price goes down.
Market Wizard Paul Tudor-Jones sums it up perfectly for me:
"At the end of the day, your job is to buy what goes up and to sell what goes down so really who gives a damn about P/E's?"
PTJ also is a believer in that "price precedes news". Given his track record, who am I to argue???
Also refer to this post here.