Shares in automakers around the world wobbled on Thursday after President Trump announced plans to impose a 25 percent tariff on imported cars and some parts beginning next week.
The stocks of major Detroit carmakers, which build some of their vehicles in Canada and Mexico, were rattled on Wall Street. Shares in General Motors, which imports many of its best-selling cars and trucks from Mexico, tumbled more than 7 percent. Ford, which is less reliant on imported cars, fell almost 4 percent, extending its losses from earlier in the day, while Stellantis’s stock — the parent of Chrysler, Fiat, Jeep, Peugeot and Ram — was more than 1 percent lower for the day.
The turmoil was concentrated in the auto sector, with the broader S&P 500 index trading roughly flat before ending the day down 0.3 percent.
But shares in Tesla, which is expected to suffer less from tariffs than its competitors because it makes all the cars that it sells in California and Texas, rose about 0.4 percent on Thursday. Mr. Trump said on Wednesday that Elon Musk, Tesla’s chief executive who has taken a leading role in the White House, had not influenced his decision to impose tariffs.
Among the hardest hit shares on Thursday were those of carmakers based in Germany, Japan and South Korea, which sell many of their cars in the United States and rely on complex supply chains that cross borders, including from production sites in Mexico and Canada.
Earlier in the day, shares in the German automaker Volkswagen, Europe’s largest, fell 1.5 percent. Other German carmakers like Mercedes-Benz and BMW dropped 2 to 3 percent in European trading.