In the current market session, Southwest Airlines Inc. LUV is trading at $38.18, after a 1.60% increase. However, over the past month, the stock decreased by 2.64%, and in the past year, by 28.85%. Shareholders might be interested in knowing whether the stock is undervalued, even if the company is performing up to par in the current session.

The stock is currently above from its 52 week low by 69.95%. Assuming that all other factors are held constant, this could present itself as an opportunity for investors trying to diversify their portfolio with Airlines stocks, and capitalize on the lower share price observed over the year.

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 indicates that shareholders do not expect the stock to perform better in the future, and that the company is probably undervalued. 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.

Depending on the particular phase of a business cycle, some industries will perform better than others.

Southwest Airlines Inc. has a better P/E ratio of 110.53 than the aggregate P/E ratio of 23.32 of the Airlines industry. Ideally, one might believe that Southwest Airlines Inc. might perform better in the future than it’s industry group, but it’s probable 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.