Anthropic launches Claude Fable 5.2, Mythos 5.2; eyes up to $69.3 billion IPO

Anthropic has unveiled two new artificial intelligence models, Claude Fable 5.2 and Claude Mythos 5.2, as the company steps up competition with OpenAI, Google and Meta while preparing for a potential blockbuster stock market listing that could raise as much as $69.3 billion.

The new models are designed for different applications. Claude Fable 5.2 is aimed at coding, reasoning and AI agent tasks, while Claude Mythos 5.2 is focused on approved cybersecurity and life-sciences research applications.

Anthropic said the latest models can generate outputs up to 30% faster than their Claude 5.1 predecessors and communicate more clearly with users. The company has also priced the models at $8 per million input tokens and $40 per million output tokens, lower than the pricing of their previous versions.

Access to Claude Mythos 5.2 will remain restricted to organisations approved through Anthropic’s verification programmes for cybersecurity and life-sciences research. Fable 5.2, meanwhile, will be available more broadly.

The launch comes as AI companies increasingly compete on coding capabilities, reasoning and the development of AI agents, which can carry out multi-step tasks with limited human intervention. Anthropic’s latest releases also follow the rollout of Claude Haiku 5.5 in October.

Anthropic’s $69.3 billion IPO plans

The model launches come against the backdrop of Anthropic’s proposed public listing. In an exclusive report, Reuters said the company was aiming to raise as much as $69.3 billion through its initial public offering, potentially making it one of the largest IPOs on record.

However, the pricing details behind the proposed offering were subsequently retracted. According to Reuters, which reviewed emails sent to investment bankers, an Anthropic representative initially circulated a securities filing showing plans to sell around 866.7 million Class A shares at a price range of $70-$80 apiece.

The proposed sale included approximately 843.3 million shares from Anthropic and another 23.3 million shares from existing shareholders. At the upper end of the indicated price range, the offering would have raised $69.3 billion.

Anthropic later sent another email informing bankers that the pricing details were inaccurate and that an updated filing would follow. The company declined to comment, while Reuters said it could not independently establish which details were incorrect. The $69.3 billion figure should therefore be treated as indicative terms in the retracted filing rather than a confirmed fundraising target.

The original filing also showed that Anthropic had lined up $26 billion in investments through a separate private placement of its Class N common stock. Google, Nvidia, Advanced Micro Devices, Broadcom, Micron Technology, Microsoft and Taiwan Semiconductor Manufacturing Company were among the companies that had agreed to participate at the IPO price, with the placement expected to close immediately after the listing. Anthropic was expected to formally begin its IPO roadshow on Tuesday, with pricing anticipated the following week, according to the report.