Altria pulled its own e-cigarettes off the market in 2018 after taking a nearly $13 billion stake in Juul. But that investment has lost more than 95% of its value as Juul's prospects have dimmed, giving Altria the option to exit its non-compete agreement. That means Juul could soon be forced to battle for space on retail shelves with Marlboro-maker Altria, along with longstanding competitors like Reynolds American's Vuse, which recently edged past Juul to become the leading U.S. vaping brand.