Interconnect, not compute, is now the binding constraint on AI clusters. Copper, pluggable optics and CPO will coexist for years, so the strongest names span both paths or own the tightest bottleneck. Top five: Credo, the fastest-growing full stack; Applied Optoelectronics, the 800G/1.6T ramp; Marvell, broadest but richly priced; Lumentum, the laser chokepoint; Tower, the foundry bet. Coherent, Amphenol, Fabrinet, GlobalFoundries, TSMC and Broadcom also gain. Astera Labs is pricier and narrower. x.com x.com x.com

