Nvidia shares fell 4% in extended trading on Wednesday after the company said the U.S. government is restricting sales in China. Nvidia said the restriction would affect the A100 and H100 products, which are graphics processing units sold to businesses. The company expects that it could lose $400 million in potential sales in the current quarter after previously forecasting revenue of $5.9 billion. The new rule also applies to sales to Russia, but Nvidia said it doesn’t have paying customers there. The only current products that the new licensing requirement applies to are A100, H100 and systems such as DGX that include them’ The company said it was applying for a license to continue some Chinese exports but doesn’t know whether the government will grant an exemption. . . .