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. Two out of the three major indices are trading up today with the Dow Jones Industrial Average ( ^DJI) trading up 68 points (0.4%) at 17,048 as of Thursday, Aug. 21, 2014, 12:55 PM ET. The NYSE advances/declines ratio sits at 1,747 issues advancing vs. 1,215 declining with 171 unchanged. The Health Services industry currently sits down 0.2% versus the S&P 500, which is up 0.3%. On the negative front, top decliners within the industry include Cyberonics ( CYBX), down 6.5%, and ResMed ( RMD), down 0.7%. Top gainers within the industry include Smith & Nephew ( SNN), up 1.2%, Grifols ( GRFS), up 0.9%, Fresenius Medical Care AG & Co. KGaA ( FMS), up 0.7% and WellPoint ( WLP), up 0.6%. TheStreet would like to highlight 3 stocks pushing the industry lower today: 3. DexCom ( DXCM) is one of the companies pushing the Health Services industry lower today. As of noon trading, DexCom is down $0.85 (-1.9%) to $43.29 on average volume. Thus far, 327,088 shares of DexCom exchanged hands as compared to its average daily volume of 732,300 shares. The stock has ranged in price between $42.98-$44.23 after having opened the day at $44.20 as compared to the previous trading day's close of $44.14. DexCom, Inc., a medical device company, focuses on the design, development, and commercialization of continuous glucose monitoring systems. DexCom has a market cap of $3.4 billion and is part of the health care sector. Shares are up 24.6% year-to-date as of the close of trading on Wednesday. Currently there are 9 analysts that rate DexCom a buy, 1 analyst rates it a sell, and 3 rate it a hold. TheStreet Ratings rates DexCom as a sell. The area that we feel has been the company's primary weakness has been its disappointing return on equity. Get the full DexCom 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.