Nvidia and Advanced Micro Devices are the latest firms caught in the escalating trade war between the U.S. and China. Nvidia disclosed in an SEC filing Tuesday evening that future sales of its H20 AI accelerators to China would require a license from the U.

The stock market took a downward turn on Wednesday after Nvidia said it would take a $5.5 billion charge due to U.S. export restrictions on H20 processors to China and other countries.

Shares in Nvidia slumped in after-hours trading late Tuesday after it said that tighter U.S. government controls on its exports of computer chips used for artificial intelligence will cost it an extra $5.