Wells Fargo Downgrades U.S. Silica To Market Perform By: Benzinga via Benzinga November 26, 2014 at 07:51 AM EST Analysts at Wells Fargo downgraded U.S. Silica Holdings (NYSE: SLCA) from Outperform to Market Perform. U.S. Silica shares have ... Read More >> Related Stocks: U.S. Silica Holdings Inc