✦ The XPU Roster & the $60-90B PrizeNarrow moat

Custom accelerators were Broadcom's decade-long apprenticeship with Google's TPU; they are now a franchise with a roster: Google formalized a long-term TPU agreement through 2031 in April 2026, Meta and Anthropic ramp their own programs, OpenAI signed its ten gigawatts, and Apple joined in 2026 — with Broadcom holding an estimated 70% of the custom-accelerator design market¹. Management sizes the serviceable market for XPUs and their networking at $60-90 billion in fiscal 2027, with each major customer planning million-XPU clusters².

The business model is the moat's best trick: the hyperscaler owns the chip design and absorbs the manufacturing capex; Broadcom supplies the hard parts — serdes, packaging, interconnect IP — and books the toll. Every custom chip a customer builds against Nvidia deepens their dependence on Broadcom. The risk is the roster's other side: five-ish customers this size can insource (Google has tried before), squeeze price, or simply pause a generation. Watch the customer count — each addition is billions — and watch Marvell and the customers' own silicon teams, the only two forces that can erode a 70% share.