The AI Trade Has a Visibility Problem

Everyone watches NVIDIA. Few watch what NVIDIA cannot route around.

The Rubin Build-Out 100 tracks 100 companies across 18 sectors forming the physical infrastructure constraint of the AI buildout. Not chip designers. Not hyperscalers. The companies that deposit, etch, package, interconnect, cool, and power the silicon.

Returns since base (1,000 = October 3, 2022): Rubin EW 4,773 (+377%). Memory 13,239 (+1,224%). Substrates 3,636 (+264%). Advanced Packaging 5,680 (+468%).

YTD leaders: Memory +61.15%. Advanced Materials +46.64%. Packaging +43.55%. High-Speed Interconnects +36.83%. Laggards: EDA & Chip IP (+1.13%), Architects/Chip Design (−7.00%). The design layer is flat while the physical layer rips.

Sector spotlight — S14, High-Speed Interconnects (10 stocks, +36.83% YTD): optical/photonics names leading — AAOI +227%, Furukawa Electric +193%, Lumentum +116%. Electrical interconnect lagging — Amphenol +1%, Astera Labs −15%, Credo −24%.

That intra-sector divergence tells you where the next bottleneck sits: photonic. 800G and 1.6T optical links at data center scale. This is what a functional index surfaces that a cap-weighted ETF never will.

18 sectors. 100 companies. 31 indices. Updated daily after market close.