China startup demoes prototype EUV light source

The real signal isn't the prototype itself—it's the explicit refusal to demo again. That restraint exposes the upstream supply chain as the true chokepoint: high-power CO₂ lasers, tin-droplet plasma chambers, and collection optics remain heavily import-dependent. A public demonstration risks triggering BIS export-control escalation clauses, further narrowing access to critical upstream components. Technically, the gap between a working prototype and production-grade output—250W+ sustained power, 1,000+ wph throughput, and integration of 100,000+ components—remains vast. ASML's moat was never a single light source; it's two decades of system-level co-optimization. Yet the capital-market pricing logic for monopoly premiums has already shifted. A credible "second-source" narrative, even five years out, is enough to compress ASML's 80%+ gross-margin expectations. Over the next 18 months, three trajectories are likely: accelerated Chinese M&A of niche EUV component startups globally; ASML doubling down on High-NA EUV to preserve generational lead; and Washington expanding the Entity List under "technology diffusion" pretexts. This prototype is, in essence, the anchor that resets the strategic clock.