Investors in Nio (NYSE: NIO) are finally getting a breather, as the electric vehicle (EV) stock began the week on a solid note after plunging nearly 9% last week. As of 12:30 p.m. ET Monday, Nio was trading up 7.3% after having surged 10.8% earlier in the day on rumors about its much-awaited flagship luxury sedan,the ET7, touted to compete with Tesla (NASDAQ: TSLA). Earlier this month, Nio dropped a bomb when it reported a sharp decline in deliveries for October, down 27.5% year over year, even as rivals continued to race ahead.