AMD, NVDA Slide 3-4% as China Rejects US Semiconductor Exports; Geopolitical Risk Spike

China's abrupt rejection of US semiconductor imports hit the sector hard on Friday. AMD fell 3.3%, NVDA dropped 2.2%, and memory chip stocks like MU sold off 5%, all while earlier US approval of H200 AI chip exports to select Chinese companies had briefly lifted spirits. The contradiction is stark: the US had just loosened export controls on advanced chips, only for Beijing to signal it will source alternatives and reduce dependency on American semiconductors.

This is not a one-day noise trade. China has made strategic investment in domestic chip design and fab capacity over the past 18 months, including support for companies like SMIC. The shift reflects a longer-term de-risking of supply chains away from US semiconductor vendors in response to escalating trade tensions under the Trump administration. Nvidia had derived roughly 25% of its revenue from China before restrictions; that window had briefly re-opened, but now appears closed again.

The broader implication: mega-cap semiconductor and AI firms are exposed to geopolitical binary outcomes that can swing earnings estimates by tens of billions of dollars in a single news cycle. NVIDIA's valuation at $5.7 trillion is partly predicated on continued access to global markets, especially Asia and China. Any further tightening of export restrictions or retaliatory moves by Beijing could upend the bull case.

Broadcom and other fabless/foundry players also felt the pressure. Samsung's selloff in Seoul triggered weakness in US futures before market open. The debate is whether this is a temporary negotiating posture by China (waiting for Trump to offer better terms) or a structural shift toward self-sufficiency. If the latter, semiconductor earnings growth could be materially constrained for years.