Anthropic cuts prices 40% ten days after its CEO said slow down

Claude Opus 5.5 launched on 22 September at $4 per million input tokens and $20 per million output, roughly 40% cheaper to run than Opus 5, with cache reads cut 60% to $0.20 per million tokens. Anthropic says it matches its own top-tier Fable 5.1 on most complex coding and knowledge work, and Reuters reported the release was accelerated after OpenAI's GPT-6 Astra started pulling developer attention. Dario Amodei published a 3,800-word essay on 12 September arguing the industry should slow the pace of frontier development on safety grounds. Ten days later his company shipped a faster, cheaper flagship model explicitly framed as a competitive response, which is an odd sequence for a company also preparing IPO paperwork it confidentially filed with the SEC in June.