NEW YORK ( TheStreet) -- Knight Transportation (NYSE: KNX) is trading at unusually high volume Thursday with 2.4 million shares changing hands. It is currently at four times its average daily volume and trading up $1.21 (+7.3%) at $17.82 as of 3:55 p.m. ET. Knight Transportation has a market cap of $1.28 billion and is part of the services sector and transportation industry. Shares are up 6.2% year to date as of the close of trading on Wednesday. Knight Transportation, Inc., together with its subsidiaries, operates as a short to medium-haul truckload carrier of general commodities in the United States. The company has a P/E ratio of 23.4, above the average transportation industry P/E ratio of 23.1 and above the S&P 500 P/E ratio of 17.7. TheStreet Ratings rates Knight Transportation as a buy. The company's strengths can be seen in multiple areas, such as its growth in earnings per share, robust revenue growth, largely solid financial position with reasonable debt levels by most measures and notable return on equity. We feel these strengths outweigh the fact that the company has had lackluster performance in the stock itself. You can view the full Knight Transportation Ratings Report. See all heavy volume stocks in our stocks moving on unusual volume list or get investment ideas from our investment research center. Interested in other stocks that are rising on unusually high volume? Get free SMS text alerts sent to you when the action happens by texting HVUP to 95370 or select from multiple alert options.