Amazon's Anthropic stake grew sharply in value in the September quarter

Amazon's September-quarter filing shows its Anthropic position carried at much higher estimated values than the principal amount of its convertible notes. Estimated fair value of the notes rose to about $146 billion as of September 30, up from about $98 billion in June, while Amazon's Anthropic nonvoting preferred stock stood at about $92.5 billion, versus $14.8 billion at the end of 2025. The gap between the $6.2 billion principal and these fair values makes the mark-to-market exposure a material swing factor in reported results.

1. Estimated fair value of Amazon's Anthropic convertible notes was $146.2 billion as of Sept. 30, up from $97.9 billion in June.
2. Amazon reported $92.5 billion in Anthropic nonvoting preferred stock, compared with $14.8 billion at the end of 2025.
3. The convertible notes carry a principal amount of about $6.2 billion.