@Puru chan:$NVIDIA Corp(NVDA)$New restrictions on exports of cutting-edge chips from Nvidia Corp to China have signaled an escalation of the U.S. crackdown on Beijing's technological prowess and alarmed investors already worried about an industry downturn.Shares of Nvidia fell 11% to $133.46 on Thursday, wiping out more than $40 billion in market value and dragging the Philadelphia SE Semiconductor Index down by more than 4%.The U.S. move to restrict exports of two of Nvidia's top computing chips for artificial intelligence - the H100 and A100 - to China could hurt the company's business in the key market, according to a filing on Wednesday.The action by Washington comes as tensions rise over access to advanced chip technology and the future of Taiwan, where