MI455X is what AMD will sell to Anthropic (in the form of complete Helios racks, with EPYC servers full of GPUs) in the deal discussed in a couple of other HN threads (Reuters title: "AMD to sell Anthropic tens of billions in AI servers, invest up to $5 billion in startup"), i.e. Anthropic will not pay all in cash, but $5B will be paid by giving a share to AMD.

so more circular cash strcuture; we're in Dot Com Boom 2: Electric GPUoogaloo