Moody's Investment Service analyst Christopher Wimmer upgraded his rating on the health care REIT Thursday to 'positive' from 'stable.' "Healthcare Realty Trust's focus on medical office buildings and outpatient services provides very good earning stability," he said in a report. Wimmer did not set a price target for the company, which he noted had a "limited opportunity to grow relative to more diversified health care REIT's, given the [medical office building]-focused nature of its platform." Shares of the company (Ticker: HR) were up to $25.56 Friday. Year to date, they're up nearly 20 percent.