Anthropic S-1 says it has met its Responsible Scaling Policy threshold

The filing's evolution is itself the story. The original Form S-1, filed 26 October 2026 for a Nasdaq listing under the symbol "ANT", cautioned that evidence on AI-driven acceleration comes from lagging indicators, and that Anthropic "may not identify a significant acceleration in our rate of development until after it has occurred." Amendment No. 1 on 2 November 2026 sharpened this into an example, saying internal estimates and expectations regarding future models — "rather than our current models" — indicated the company might imminently meet the Responsible Scaling Policy definition. That version also said no current model had been designated as exceeding the threshold.

Amendment No. 2 on 10 November 2026 crossed that line, stating that Anthropic's use of AI systems has already been accelerating its research and development. Because the threshold applies where the company observes or expects a specified degree of accelerated progress, the filing says the determination was made on what it expects from future models and its overall rate of progress, rather than on what it has observed from current models. The filing adds that Anthropic continues to assess the underlying data and will release further reports.

The same section notes that precautionary measures have in the past included delaying model releases and limiting initial availability, and that future measures could affect whether, how and when new models are developed or deployed. For research administrators, the practical weight of the document is that it is a dated, legally accountable primary source — distinct from a blog post — while still describing the issuer's own assessment rather than an outside measurement.