Shares of General Motors and Stellantis fell Tuesday after President-elect Donald Trump threatened to impose a 25 tariff on goods imported from Canada and Mexico. The proposed tariffs would significantly affect the automotive industry, which relies on lower-cost production in Mexico. UBS reports that the automotive sector accounts for 26 of U.S. imports from Mexico and 12 from Canada. GM and Stellantis saw significant drops in their stock prices, while other automakers like Ford and Toyota also experienced declines.