Editor's Note: Any reference to TheStreet Ratings and its underlying recommendation does not reflect the opinion of TheStreet, Inc. or any of its contributors including Jim Cramer or Stephanie Link. All three major indices are trading up today with the Dow Jones Industrial Average ( ^DJI) trading up 67 points (0.4%) at 16,436 as of Friday, Aug. 8, 2014, 12:55 PM ET. The NYSE advances/declines ratio sits at 1,992 issues advancing vs. 961 declining with 169 unchanged. The Health Care sector currently sits up 0.3% versus the S&P 500, which is up 0.4%. On the negative front, top decliners within the sector include Salix Pharmaceuticals ( SLXP), down 5.4%, Pharmacyclics ( PCYC), down 3.2%, AstraZeneca ( AZN), down 2.8%, Mylan ( MYL), down 1.6% and HCA Holdings ( HCA), down 1.3%. Top gainers within the sector include Air Methods ( AIRM), up 11.3%, Taro Pharmaceutical Industries ( TARO), up 3.6%, Allergan ( AGN), up 2.7%, Valeant Pharmaceuticals International ( VRX), up 1.4% and Humana ( HUM), up 1.1%. TheStreet would like to highlight 3 stocks pushing the sector lower today: 3. Volcano ( VOLC) is one of the companies pushing the Health Care sector lower today. As of noon trading, Volcano is down $4.04 (-25.6%) to $11.74 on heavy volume. Thus far, 4.3 million shares of Volcano exchanged hands as compared to its average daily volume of 590,500 shares. The stock has ranged in price between $11.54-$13.25 after having opened the day at $13.11 as compared to the previous trading day's close of $15.78. Volcano Corporation designs, develops, manufactures, and commercializes a suite of precision guided therapy tools primarily to physicians, nurses, and technicians worldwide. The company operates in two segments, Medical and Industrial. Volcano has a market cap of $835.5 million and is part of the health services industry. Shares are down 27.8% year-to-date as of the close of trading on Thursday. Currently there are 6 analysts that rate Volcano a buy, no analysts rate it a sell, and 9 rate it a hold. TheStreet Ratings rates Volcano as a sell. The company's weaknesses can be seen in multiple areas, such as its deteriorating net income, disappointing return on equity, generally high debt management risk, generally disappointing historical performance in the stock itself and feeble growth in its earnings per share. Get the full Volcano 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.