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,

The ban on sales of the H20 chips calls into question the company’s ability to continually beat Wall Street’s lofty expectations.

Nvidia's shares plunged almost 7% in after-market trading, amid a broader slump in global markets as Trump's new ban intensifies a U.S.-China tech war.