Dunkin' Shares Tumble Following Guggenheim Downgrade By: Benzinga via Benzinga March 07, 2016 at 11:36 AM EST Shares of Dunkin Brands Group Inc (NASDAQ: DNKN) fell as much as 6 percent Monday after Guggenheim downgraded the stock to Neutral from ... Read More >> Related Stocks: Dunkin' Brands Group