Benzinga's Top Upgrades, Downgrades For May 31, 2017 By: Benzinga via Benzinga May 31, 2017 at 09:21 AM EDT Top Upgrades Maxim Group upgraded Potbelly Corp (NASDAQ: PBPB) from Hold to Buy. Potbelly shares rose 0.46 percent to close ... Read More >> Related Stocks: Akari Therapeutics ADR Antero Midstream Gp LP Beacon Roofing Suppl Cadence Bank Codexis Inc Cui Global Inc Donaldson Company Francesca's Holdings Gogo Inc Irobot Corp Koppers Holdings Inc Lloyds Banking Group Plc ADR Molina Healthcare Inc Park Hotels & Resorts Inc Potbelly Corp Vmware Inc Zebra Technologies