General Motors (GM)’s stock rose by 44%, in the past six months, driven by an extraordinary increase in the P/E multiple, even as revenue declined. BROWNSTOWN TOWNSHIP, MI - AUGUST 13: A Chevrolet Volt extended-range electric vehicle sits at an event where Fritz Henderson, CEO and President of General Motors, announced that GM will invest $43 million in Brownstown Township, Michigan to manufacture lithium-ion battery packs for the Chevrolet Volt and other extended-range electric vehicles at the GM Brownstow ...