Heavy equipment producer Caterpillar (CAT) returned to the Green Favored Zone in the SIA S&P 100 Index Report yesterday for the first time since June. A summer drop into the red zone bottomed out between July and September. This month, CAT’s relative strength has improved with a climb back up the rankings accelerating. Yesterday it finished in 21st place, up 5 spots on the day and up 47 positions in the last month.