General Motors stock is among today’s top performers. Why are GM shares rallying?Falling Oil Prices Could Support GM DemandGM stock appears to be benefiting from the sharp drop in crude because lower oil prices can directly improve consumer affordability and sentiment around vehicle purchases. West Texas Intermediate crude fell more than 8% to about $90.10 a barrel, while Brent dropped nearly 8% to roughly $103.31 after Trump said the U.S. had held "very good and productive conversations" with Tehran and wo ...