Discount retailers, shoe manufacturers and steel makers have staged a sharp comeback amid merger activity and strong performances by a handful of companies. Steel Dynamics (STLD) leads the steel producers industry group with a 95 Composite Rating, followed closely by U.S. Steel (X) at 92. As of Thursday, the two have powered the group of 20 stocks to No. 20 out of the 197 industries that IBD tracks. It was at No. 174 just six weeks ago.