Nvidia shares are tumbling Wednesday as the firm said it expects to take a $5.5 billion first-quarter charge after the U.S. limited exports of its artificial intelligence chips to China. AMD expects an $800 million charge and its stock also is falling.

Nvidia shares have fallen more than 5% in after-hours trading after the US said the chipmaker would require a licence to sell H20 chips to China. View on euronews

Nvidia did not warn at least some major customers in advance about new U.S. export rules it was told about a week ago requiring it to obtain licenses to sell its China-focused artificial intelligence chip,