RBC Upgrades HollyFrontier, Notes Improving Operational Execution By: Benzinga via Benzinga May 07, 2015 at 11:32 AM EDT In a report published Thursday, RBC Capital Markets analyst Brad Heffern upgraded shares of HollyFrontier Corp (NYSE: HFC) to ... Read More >> Related Stocks: Brent Crude Holly Energy Partners LP Hollyfrontier Corp Maui Land & Pineapple Company WT Offshore