RBC Cuts Helmerich & Payne, U.S. Silica On Valuation; Sees Little Upside By: Benzinga via Benzinga September 20, 2015 at 11:24 AM EDT Analysts at RBC Capital Markets downgraded Helmerich & Payne, Inc. (NYSE: HP) and U.S. Silica Holdings Inc (NYSE: SLCA) from ... Read More >> Related Stocks: Helmerich & Payne RBC Bearings Inc U.S. Silica Holdings Inc