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 All three major indices are trading up today with the Dow Jones Industrial Average ( ^DJI) trading up 127 points (0.8%) at 15,307 as of Tuesday, June 18, 2013, 12:45 PM ET. The NYSE advances/declines ratio sits at 2,604 issues advancing vs. 474 declining with 57 unchanged. The Health Services industry currently sits up 0.4% versus the S&P 500, which is up 0.6%. On the negative front, top decliners within the industry include Medtronic ( MDT), down 1.46, and HCA Holdings ( HCA), down 0.94. Top gainers within the industry include UnitedHealth Group ( UNH), up 1.2%, Abbott Laboratories ( ABT), up 1.1% and Aetna ( AET), up 1.0%. TheStreet Ratings group would like to highlight 4 stocks pushing the industry lower today: 4. Catamaran ( CTRX) is one of the companies pushing the Health Services industry lower today. As of noon trading, Catamaran is down $0.70 (-1.3%) to $52.83 on light volume Thus far, 427,920 shares of Catamaran exchanged hands as compared to its average daily volume of 1.7 million shares. The stock has ranged in price between $52.83-$53.66 after having opened the day at $53.53 as compared to the previous trading day's close of $53.53. Catamaran Corporation provides pharmacy benefit management (PBM) services and healthcare information technology (HCIT) solutions to the healthcare benefits management industry in North America. The company operates in two segments: PBM and HCIT. Catamaran has a market cap of $11.0 billion and is part of the health care sector. The company has a P/E ratio of 72.5, above the S&P 500 P/E ratio of 17.7. Shares are up 13.7% year to date as of the close of trading on Monday. Currently there are 16 analysts that rate Catamaran a buy, no analysts rate it a sell, and 3 rate it a hold. TheStreet Ratings rates Catamaran as a buy. The company's strengths can be seen in multiple areas, such as its robust revenue growth, largely solid financial position with reasonable debt levels by most measures, good cash flow from operations, compelling growth in net income and growth in earnings per share. We feel these strengths outweigh the fact that the company has had somewhat disappointing return on equity. Get the full Catamaran Ratings Report now. STOCKS TO BUY: TheStreet Quant Ratings has identified a handful of stocks that can potentially TRIPLE in the next 12-months. Learn more.