Move follows admission of affair with woman alleged to be Chinese spy and reported relationship with employee

Shares in Nvidia plunged by 13% when Wall Street opened, after Huang’s departure was announced. After a partial rebound, they were down 7% in morning trading, wiping more than $320bn (£242bn) off Nvidia’s value on the day and more than $600bn for the week – valuing the company at about $3.9tn.