The Chinese EV maker looks undervalued relative to its growth potential.Nio's (NIO 3.50%) stock surged 14% on Sept. 5 after the Chinese electric vehicle (EV) maker posted its second-quarter report. Its revenue rose 99% year over year to 17.45 billion yuan ($2.4 billion) but missed analysts' estimates by $40 million. It narrowed its adjusted net loss per American depositary share (ADS) from 3.28 yuan to 2.21 yuan ($0.30), which matched the consensus forecast.Nio didn't hit a home run, but its soaring deliver ...