Chinese stocks fell, but investors in Nio shouldn't worry.Nio (NIO -7.14%) stock, which was holding up well until yesterday since its jaw-dropping rally in September, reversed course this morning and plunged 10% within minutes of the market's opening. Shares of the Chinese electric vehicle (EV) maker were trading a little over 7% lower as of 11:30 p.m. ET Tuesday.There's nothing wrong with Nio. Chinese stocks were crashing all across the board today, and Nio was no exception. It is, after all, one of the le ...