Editor's Note: TheStreet ratings do not represent the views of TheStreet's staff or its contributors. Ratings are established by computer based on metrics for performance (which includes growth, stock performance, efficiency and valuation) and risk (volatility and solvency). Companies with poor cash flow or high debt levels tend to earn lower ratings in our model. NEW YORK ( TheStreet) -- Southwest Airlines (NYSE: LUV) hit a new 52-week high Monday as it is currently trading at $12.59, above its previous 52-week high of $12.55 with three million shares traded as of 2:20 p.m. ET. Average volume has been 7.4 million shares over the past 30 days. Southwest Airlines has a market cap of $9.14 billion and is part of the services sector and transportation industry. Shares are up 20.9% year to date as of the close of trading on Friday. Southwest Airlines Co. operates passenger airlines that provide scheduled air transportation services in the United States. As of December 31, 2012, the company operated 694 aircraft, including 606 Boeing 737 aircraft and 88 Boeing 717 aircraft. The company has a P/E ratio of 22.4, above the S&P 500 P/E ratio of 17.7.