 UBS Group AG increased its holdings in shares of Houghton Mifflin Harcourt Co NASDAQ:HMHC by 156,397.3 during the fourth quarter, HoldingsChannel.com reports. The institutional investor owned 284,825 shares of the business services providers stock after purchasing an additional 284,643 shares during the quarter. UBS Group AGs holdings in Houghton Mifflin Harcourt were worth 1,781,000 as ... 