The price to earnings ratio (PER, P/E or PE) is a measure used in market analysis, and it is calculated by dividing the market capitalization of a company with their net income (earnings), or by dividing the price of a share by the earnings per share. These operations are performed generally with the data of the last financial year of a company, but some financial analysts use either quarterly data (PER sliding) or forecast data based on earning expectations (projected PER).
The PER is used to evaluate the value of a stock relative to the prices of securities of companies in the same industry and sector: the lower the PER, the cheaper the action. The PER may also reveal the speculation of investors, who expect a strong increase in future earnings: in this case, the higher the PER, the higher the expected increase in profits.
There are two methods to interpret P/E ratio:
Thus, PER can be interpreted as a sort of inverted yield, between "potential" income of the stock and its price.
In practice, this ratio varies between 5 and 40, sometimes with extreme (although lower or higher) that depend on the type of business (growth company, defensive, cyclical crisis, declining ...) , the economic cycle, the listing market, etc. In short, many interpretations are possible and there is no ideal and theoretical value. Therefore, the list below is indicative and should not be used as a fix guide: