INVESTIGATION ALERT: Fields Kupka & Shukurov LLP Is Investigating Rosetta Stone Inc. for Potential Breach of Fiduciary Duty Claims. NEW YORK, April 30, 2020 (GLOBE NEWSWIRE) -- Fields Kupka & Shukurov LLP is investigating potential breach of fiduciary duty claims involving the board of directors of Rosetta Stone Inc. (NYSE:...