These are the top-performing S&P 500 stocks of 2015 By: MarketWatch March 27, 2015 at 04:30 AM EDT The Health Care sector continues its ascent even as the benchmark index stumbles, writes Phil van Doorn. Read More >> Related Stocks: AbbVie Alexion Pharmaceuticals Berkshire Hathaway Boston Scientific Celgene Corp First Solar Gilead Sciences Goldman Sachs Group Hospira Kraft Foods Group Mallinckrodt plc Martin Marietta Materials S&P Biotech SPDR Skyworks Solutions Standard & Poors 500 Tenet Healthcare Urban Outfitters Valero Energy Vulcan Materials