Nio is one of the many growth stocks crashing ahead of the Federal Reserve's policy, though investors in the EV manufacturer have been gripped by more than just inflationary fears. What happened Electric vehicle (EV) stock Nio (NYSE: NIO) was in free fall today, slumping as much as 10% as of 12:20 p.m. Not surprisingly, cautious investors appear to be dumping their shares in Chinese EV maker Nio while they still can.