The Trump administration’s chaotic pronouncements on tariffs caused more uncertainty among investors. America’s customs agency said that smartphones, computers and chips, among other things, would be exempt from Donald Trump’s punitive levies, only for the president to say later that the exemptions would be temporary, as nobody is getting “off the hook”. Tech products will be exempt from reciprocal tariffs for a time but included in other duties on the chip industry that may be two months away, said Howard Lutnick, the commerce secretary, sowing more confusion. Mr Trump also said he was looking to help car companies, though without saying how.