Stocks fell sharply Monday after China said it would increase tariffs on as much as $60 billion worth of U.S. imports to as high as 25%. shares tumbled more than 5% as investors worried about the impact of China's tariffs on the tech giant. Stocks were down sharply Monday after China said it would increase tariffs on as much as $60 billion worth of U.S. imports to as high as 25% following last week's collapse of trade talks between the world's two largest economies.