On Monday, AtriCure (ATRC) received an upgrade to its Relative Strength (RS) Rating, from 66 to 72. When To Sell Stocks To Lock In Profits And Minimize Losses IBD's proprietary rating identifies price performance with a 1 (worst) to 99 (best) score. The score shows how a stock's price performance over the trailing 52 weeks stacks up against all the…