A Tesla car is driven past a store of the electric vehicle (EV) maker in Beijing, China January 4, 2024. Florence Lo | ReutersIt was a brutal first quarter for Tesla investors.Shares of the electric vehicle maker plunged 29% in the first three months of the year, the worst quarter for the stock since the end of 2022 and the third worst since Tesla went public in 2010. It was also the biggest loser in the S&P 500.Chief among concerns on Wall Street is Tesla's core business. The company is poised ...