Nvidia expects to take $5.5bn hit as US tightens AI chip export rules to China

**Summary:** - Nvidia expects a $5.5bn loss due to the U.S. government blocking sales of its H100 AI chips in China, citing national security concerns about potential supercomputer use. - This announcement caused Nvidia's shares to drop 6% after hours, and shares of other chipmakers like Samsung Electronics, SK Hynix, ASML, and Advanced Micro Devices also fell. - The U.S. Department of Commerce is investigating the impact of chip imports on national security. - Nvidia plans to invest up to $500bn in AI infrastructure in the U.S. over the next four years to expand its manufacturing presence.