Are Caterpillar's dark days over? Image source: Getty Images.Analysts are turning increasingly bullish on Caterpillar Inc. (NYSE: CAT), with the biggest rating upgrade coming from Deutsche Bank: It rated Caterpillar stock a buy with a 12-month price target of $98, or almost 20% upside from current prices. That's huge given that Caterpillar is already up about 20% year to date.