Nio may be about to report a sharp increase in electric vehicle sales.Nio (NIO 10.93%) stock has been on a tear lately, and that continued as this trading week got underway. The Chinese electric vehicle (EV) maker's American depositary shares jumped as much as almost 15% this morning. As of 2:45 p.m. ET, those shares were still trading higher by 11.1%.Today's move comes after a Wall Street analyst became bullish on the company and its new mass-market brand. The stock is now up by about 33% over the last thr ...