Define the P/E valuation method. Under what circumstances should a stock be valued using this method?

The P/E ratio specifies how much investors are willing to pay for each dollar of a stock's earnings.  A high P/E ratio specifies that investors believe the stock's earnings will enhance, or that the risk of the stock is little, or both.

Financial analysts habitually use a P/E model to calculate common stock value for businesses that aren't public.  First, analysts compare the P/E ratios of alike companies within an industry to determine an appropriate P/E ratio for companies in that industry.  Second, analysts calculate a suitable stock price for firms in the industry by multiplying each firm's earnings per share (EPS) by the industry average P/E ratio.