Mercedes is quietly becoming Tesla's biggest rival

Mercedes-Benz Daimler is investing $11 billion to electrify its fleet of vehicles by 2020. Tesla's stock has rivaled General Motors and Ford as people continue to clamor for the high-tech, electric vehicles. The two automakers will compete in 2020 when they release their battery-powered SUVs. Tesla has had a meteoric rise as an underdog company, butthe next five years could be its biggest challenge yet. Major automakers from across the globe are preparing massive electric-car rollouts, perhaps n...