Falling deliveries and lower margins hit the electric vehicle maker, but the worst could be behind it.While most electric vehicle (EV) stocks had a rough start to 2024, Nio (NIO -5.92%) is among the worst-performing EV stocks of the year so far. Shares of the Chinese EV maker plunged 54.1% in the first half of 2024, according to data provided by S&P Global Market Intelligence.Things haven't been easy for Nio, but the company is focused on its growth plans, and its deliveries are finally improving. So, could ...