US tightens chip export restrictions to China, May 28

What this means

The new restrictions are narrower than the headlines suggest, but they hit where it matters most for AI hardware. Nvidia loses its workaround chip for the Chinese market. ASML can't ship the most advanced lithography machines. Samsung and SK Hynix have to choose between US technology access and their largest customer. The companies most exposed already adjusted their forecasts — but their suppliers, customers, and Chinese chipmakers are only starting to.

Evidence — 7 corpus sources

US BIS export control update — May 28 2026

New restrictions targeting AI training chips and advanced lithography equipment. Closes workaround pathways established under prior controls.

Nvidia China revenue exposure

China represented ~15-17% of Nvidia data center revenue at last public disclosure. H20 modified chip was the compliance-path product now restricted.

ASML — EUV and DUV export controls

Most advanced EUV machines already restricted since 2023. New controls extend to additional DUV configurations. Chinese capacity build-out pace directly constrained.

Samsung / SK Hynix HBM supply chain

Both suppliers use US manufacturing equipment. Compliance with US controls required for continued US market access. HBM supply to Chinese AI customers is the pressure point.

2018–19 ZTE / Huawei restriction precedent

Supply chain reorganisation ran 18–24 months. Alternative supplier ecosystem development lagged restrictions by 2–3 years.

2022 initial CHIPS Act and semiconductor controls

First wave of advanced chip controls. Chinese domestic alternative (SMIC N+2) remained 2 generations behind at 2026 assessment.

v300 methodology — Customer cascade transmission

Exposure analysis extends through a company's customer base into the sectors those customers operate in. Supplier cascade runs in parallel: Nvidia's suppliers, ASML's raw material chain, memory packaging ecosystem.