A Big Day For Biotech And It's Not Going So Well By: Benzinga via Benzinga July 27, 2015 at 13:10 PM EDT After the S&P 500 lost 1.1 percent last week, the worst weekly showing by the benchmark U.S. index in four months, U.S. stocks ... Read More >> Related Stocks: Amgen Biogen Idec Gilead Sciences Nasdaq Biotechnology Ishares ETF S&P Biotech SPDR