Anthropic is nearing the completion of a deal to raise more than $20 billion in a funding round co-led by investors including Peter Thiel’s Founders Fund, D.E. Shaw & Co. and Dragoneer Investment Group, according to people familiar with the matter — adding to the artificial intelligence company’s roster of backers in one of the largest startup funding rounds ever.

Other co-leaders in the round include Iconiq and MGX, said one of the people, who asked not to be identified because the information is private. These firms will invest alongside Coatue Management and Singapore’s GIC, which are expected to lead the financing, Bloomberg previously reported.

Representatives for Founders Fund and Iconiq declined to comment. Anthropic, D.E. Shaw, Dragoneer and MGX didn’t immediately respond to requests for comment.

Anthropic is set to be valued at about $350 billion in the deal, a figure that doesn’t include dollars raised, and could be announced as early as this week, Bloomberg has reported. That valuation nearly doubles Anthropic’s prior value, cementing it as one of the world’s richest startups. The deal comes roughly five months after the company raised $13 billion — a sign of an investor frenzy buoyed by the AI developer’s soaring revenue run rate, which crossed $9 billion last year.

The funding round has become a who’s who of Silicon Valley and Wall Street investors. Other participants include Accel, Blackstone, BlackRock, TPG, Goldman Sachs Alternatives, Insight Partners and Fidelity, the people said.

Microsoft Corp. and Nvidia Corp., which have previously said they would cumulatively invest up to $15 billion in Anthropic, are also slated to participate, the person said.

Representatives for Microsoft, Nvidia and the investment firms didn’t comment on the deal.

Several of the backers in Anthropic’s new round, including Founders Fund, have previously invested in OpenAI, breaking the long-held Silicon Valley taboo of putting money into competing companies. The rapidly rising valuations of AI startups have fueled an investing frenzy that has rendered many of the Valley’s old norms obsolete.

Founded in 2021 by former employees of OpenAI, Anthropic has positioned itself as a reliable, safety-conscious firm that users can trust. While it’s smaller than OpenAI, the company’s Claude chatbot and underlying technology have gained traction with enterprise customers in sectors like software engineering, finance and health care.

Anthropic has had a banner start to the year. The company’s quiet release of a tool to automate certain legal work helped spark a market meltdown, particularly among software stocks. Days later, Anthropic unveiled a new AI model optimized for automating enterprise work tasks, including financial research, leading to a decline in shares for financial services firms.

Several of the backers in Anthropic’s new round, including Founders Fund, have previously invested in OpenAI, breaking the long-held Silicon Valley taboo of putting money into competing companies. The rapidly rising valuations of AI startups have fueled an investing frenzy that has rendered many of the Valley’s old norms obsolete.

Founded in 2021 by former employees of OpenAI, Anthropic has positioned itself as a reliable, safety-conscious firm that users can trust. While it’s smaller than OpenAI, the company’s Claude chatbot and underlying technology have gained traction with enterprise customers in sectors like software engineering, finance and health care.

Anthropic has had a banner start to the year. The company’s quiet release of a tool to automate certain legal work helped spark a market meltdown, particularly among software stocks. Days later, Anthropic unveiled a new AI model optimized for automating enterprise work tasks, including financial research, leading to a decline in shares for financial services firms.

— By Ryan Gould, Natasha Mascarenhas and Shirin Ghaffary (Bloomberg News)