AMD says US rule on chips to China could cost it $800 mn

The Silicon Valley company's earnings warning, filed with the US Securities and Exchange Commission (SEC), came a day after rival Nvidia notified regulators that it expects a $5.5 billion hit this quarter from licensing requirements on the main chip it can legally sell in China. Wall Street stocks overall tumbled Wednesday as the Federal Reserve chief warned of the drag from President Donald Trump's tariffs, with Nvidia sinking on costs connected to the US-China trade war. US officials last week told Nvidia it must obtain licenses to export its H20 chips to China because of concerns they may be used in supercomputers there, the Silicon Valley company said in a SEC filing.