Why Rivian and Ford Stocks Soared in July but Nio Dropped

July was a big month for U.S.-based electric vehicle (EV) stocks. While the S&P 500 jumped more than 9%, shares of Rivian Automotive (NASDAQ: RIVN) and Ford (NYSE: F) trounced that with returns of 33.3% and 32%, respectively, according to data provided by S&P Global Market Intelligence. The American depositary shares of Chinese electric automaker Nio (NYSE: NIO) were actually down over 9% for the month.