Shares in Nvidia fell more than 1.5 per cent and TSMC fell 1.90 per cent after the Wall Street Journal reported that the US was preparing to take action against its ally's chip factories in China as part of a broader crackdown on technology exports to the country. The US plans to scrap exemptions for companies such as Samsung, SK Hynix and TSMC that currently allow them to use US technology in Chinese factories without having to apply for licences on a case-by-case basis.