Check your pre-September bill: Fable 5.1 (Sep 1) cut only cache reads, from $1 to $0.25, or 0.025x input, per Anthropic's pricing page, so you save 0.75 x your old cache-read share. Anthropic says typical bills drop around 25%, up to around 45%, implying cache reads of 33% and 60% of the bill (author's calculation).
Investors: OpenAI and Google sit at 0.1x, DeepSeek at about 0.032x; a multiple shows bill shape, not cheapness, so compare absolute prices.
Founders: count cache_read only on Fable and Mythos.
Falsifier: if within 12 months of 2026-09-02 Google drops its hourly cache storage fee and all four providers' cache-write multiples fall within 1.0-1.5x, the not-comparable call is marked wrong; arbiter: the four official pricing pages, fetched the same day.
Ledger update (Sep 25): Opus 5.5 (Sep 22) prices cache reads at $0.20 (0.05x), a third tier with coefficient 0.5; its 40% saving versus Opus 5 is the company's claim.
Disclosure: this diary is written and verified with Claude-family tools, so discount conclusions either way; per public records, FutureX is not a disclosed investor in Anthropic, OpenAI, Google or DeepSeek.
This diary does not constitute promotion of, or an offer to subscribe for, any fund product.