Anthropic is considering releasing a new model earlier than planned after OpenAI's GPT-6 Astra launched and began taking enterprise share, Reuters reported on September 19. According to the report, the company has also discussed moving up its release schedule, while its IPO plan may be delayed until November.

The trigger: roughly two weeks after Astra's launch, it captured about 13% of enterprise AI spending, compared with about 8% for Anthropic's Fable series. The shift showed up even more sharply on OpenRouter, the developer routing platform. OpenRouter analyst Peter Walker said OpenAI's share rose to about 65% in the first week of September, while Anthropic fell to about 35% — the first time in two and a half years that OpenAI overtook Anthropic on the platform.

That reversal ends a long run of dominance. OpenRouter's weekly token-usage data showed Anthropic holding more than 50% of platform share from January through June 2026 before Astra's launch. After Astra went live, OpenAI's share climbed quickly while Anthropic's declined.

Anthropic isn't standing still. It released Claude Fable 5.1 on September 1 — two days before Astra — and cut cache-read prices by 75%. OpenAI released Astra on September 3, and CEO Sam Altman said the company was working to get Astra to everyone as quickly as possible.

The news lands days after another striking development: on September 12, Anthropic CEO Dario Amodei published an essay calling for AI development to slow down — and Sam Altman and Elon Musk later publicly agreed with him. Reuters notes that seven days after the essay, it reported Anthropic was considering changing its release pace and bringing out a new model sooner than planned.

For developers and tool buyers, the takeaway is a market in motion: the two frontier labs are now trading blows on cadence, pricing and enterprise share almost weekly, which means model choices you lock in today may look different by the holidays.

Sources