Chip Exports to China at Risk on New U.S. Rules, Sparking Selloff

(Bloomberg) — The latest U.S. effort to restrict chip exports to China from Nvidia Corp. and Advanced Micro Devices Inc. sparked concern that escalating government actions could cut off some of the semiconductor industry’s biggest companies from the largest market for their products.

Nvidia’s stock tumbled as much as 12% on Thursday after warning that new rules on the export of some artificial-intelligence chips to China may affect hundreds of millions of dollars in revenue. The Philadelphia Stock Exchange Semiconductor Index shed as much as 2.5%, adding to losses that have wiped out a third of its valuation this year.