Looking into the current session, Reliance Steel & Aluminum Inc. RS is trading at $162.20, after a 1.99% drop. Over the past month, the stock fell by 2.52%, but over the past year, it actually went up by 69.88%. With questionable short-term performance like this, and great long-term performance, long-term shareholders might want to start looking into the company's price-to-earnings ratio.

Assuming that all other factors are held constant, this could present itself as an opportunity for shareholders trying to capitalize on the higher share price. The stock is currently under from its 52 week high by 10.49%.

The P/E ratio is used by long-term shareholders to assess the company's market performance against aggregate market data, historical earnings, and the industry at large. A lower P/E can either represent a company's poor future earnings potential or a buying opportunity relative to other stocks. It shows that shareholders are less than willing to pay a high share price, because they do not expect the company to exhibit growth, in terms of future earnings.

Most often, an industry will prevail in a particular phase of a business cycle, than other industries.

Compared to the aggregate P/E ratio of 16.82 in the Metals & Mining industry, Reliance Steel & Aluminum Inc. has a higher P/E ratio of 18.68. Shareholders might be inclined to think that Reliance Steel & Aluminum Inc. might perform better than its industry group. It's also possible that the stock is overvalued.

There are many limitations to price to earnings ratio. It is sometimes difficult to determine the nature of the earnings makeup of a company. Shareholders might not get what they're looking for, from trailing earnings.