Relative to other airline companies JetBlue’s (NASDAQ:JBLU) stock prices pretty low. JetBlue’s book value per share is $6.84 and the stock is trading at $6.26. Other airline companies are trading significantly above their book value. Here is a look: Company 8/21/2013 Stock Price Book value per share PE Ratio JetBlue (NASDAQ:JBLU) $6.27 $6.84 20.3 Alaska Air (NYSE:ALK) $58.65 $22.08 12.3 Spirit (NASDAQ:SAVE) $30.87 $9.07 18.3 Allegiant (NASDAQ:ALGT) $94.45 $22.91 20.6 (Data Source: Seeking Alpha, Money.com, Yahoo Finance, Companies Balance Sheets) With the exception of Alaska Air, all of the above airline companies have relatively the same PE. JetBlue is the only one of the four that is trading below book value. Other companies like Delta has a negative book value. There is a reason for this valuation, however, compared to other airline companies, JetBlue has a bad balance sheet. Alaska Air has positive net cash (total cash - liabilities) so does Spirit and Allegiant. Moreover, JetBlue also has a high debt-to-equity ratio compared with the other three. Overall, JetBlue does not have a strong balance sheet when compared to like companies in the industry. According to seeking Alpha, however, JetBlue’s balance sheet should strengthen in the next few years as the company continues to develop. According to them, investors are not taking this into account.