David Einhorn’s Greenlight Capital has reported a stake in struggling retailer Macy’s, joining with activist hedge fund Starboard Value as a shareholder in the 158-year old company. Starboard has been pushing for Macy’s to maximize the value of its real estate holdings.  The stake was disclosed in a fourth-quarter update sent to Greenlight Capital investors in which Einhorn explains 2015’s dismal -20.2% performance. Einhorn noted that his firm has “never had a year where so little went right,” according to Reuters, and pledged to make 2016 better. Despite the drawdown, redemptions have been “modest” and a few clients have inquired...