Electric vehicle (EV) start-ups are near the top of the risk spectrum, and several stocks are plunging accordingly. Rivian Automotive (NASDAQ: RIVN) and Lucid Group (NASDAQ: LCID) are two domestic producers that were down 5.9% and 9%, respectively, as of 10:45 a.m. ET. China-based Nio (NYSE: NIO) was also deeply in the red, down 10.8%.