Anthropic and OpenAI rivalry intensifies ahead of IPOs

Relations soured further when Altman was briefly ousted by OpenAI’s board in 2023.

The rivalry between Anthropic and OpenAI has become one of the defining battles of the AI era, shaping not only the pace of innovation but also the financial and cultural narratives around artificial intelligence. What began as a split between two groups of researchers has escalated into a corporate feud that now spans Wall Street, Silicon Valley, and global politics.

The race to IPO

Both companies are racing to go public, seeing a first listing as a way to set the tone for how investors value frontier AI firms. Anthropic filed confidentially with U.S. regulators on June 1, catching OpenAI off guard. OpenAI followed a week later, targeting a September IPO at a valuation near $1 trillion. The timing is critical: whichever company lists first will influence how investors and analysts benchmark the sector.

Altman vs. Amodei

At the heart of the rivalry are two former colleagues: Sam Altman, OpenAI’s CEO, and Dario Amodei, Anthropic’s co‑founder and CEO. Amodei left OpenAI in 2020 with several researchers, citing concerns about safety and governance. His departure was seen internally as a rebuke of Altman’s aggressive approach. Since then, the two have clashed repeatedly, with each company’s product releases spurring the other to accelerate its own.

Altman pushed OpenAI to release ChatGPT in November 2022 after hearing rumors of Anthropic’s Claude chatbot. ChatGPT became the fastest‑growing consumer app in history, forcing Anthropic to play catch‑up. But by late 2025, Anthropic flipped the dynamic with a powerful update to Claude Code, prompting OpenAI to refocus on enterprise software and coding tools.

Wall Street complications

The rivalry has spilled into finance. Both companies are working with many of the same banks, creating conflicts of interest. Advisers have had to erect internal barriers between deal teams to prevent leaks. Executives at both firms have pressed bankers for intelligence on the other’s plans, underscoring the intensity of the competition.

Disputes over revenue reporting

The feud extends to accounting. OpenAI has accused Anthropic of overstating revenue by billions by booking gross sales, including amounts later passed to cloud partners like Amazon and Google. OpenAI reports net revenue after paying Microsoft. Anthropic insists its method is standard practice, portraying itself as the “principal” in transactions. Analysts say whichever company goes public first could set the precedent for how AI firms report financials.

Internal tensions

OpenAI’s rush toward an IPO has created friction inside the company. Altman reportedly clashed with CFO Sarah Friar over whether the firm could meet listing obligations on such a compressed timeline. Friar has since reassured advisers that leadership is aligned, but the episode highlights the strain of competing with Anthropic.

A long‑running feud

The rivalry dates back to Anthropic’s founding. Amodei’s decision to prioritize safety was a direct challenge to Altman’s philosophy. Since then, the companies have diverged in strategy: OpenAI has leaned heavily on consumer subscriptions, while Anthropic has focused on enterprise clients. Their competition has accelerated innovation but also deepened mistrust.

Relations soured further when Altman was briefly ousted by OpenAI’s board in 2023. Directors even considered merging with Anthropic under Amodei’s leadership, a proposal that enraged OpenAI staff. Altman was reinstated within days, but the episode left scars.

Public clashes

The feud has become increasingly visible. Altman criticized Anthropic’s Super Bowl ads as “deceptive.” Amodei accused Altman of exploiting Anthropic’s Pentagon dispute. At an AI summit in India, Prime Minister Narendra Modi urged tech leaders to join hands in unity. Altman and Amodei, standing side by side, refused — a moment captured in a viral video.

The stakes

The rivalry is not just about corporate pride. It is shaping how quickly AI tools are released, what features they include, and how they are monetized. Analysts say the competition has accelerated the generative AI boom, forcing both companies to innovate faster than they might have otherwise.

As one industry observer put it: “It’s all‑out war between these guys. Every time there’s a new release from Anthropic, the bet will be that OpenAI is soon to follow and vice versa.”

With IPOs looming, the battle is entering a new phase. The outcome will influence not only the fortunes of Altman and Amodei but also how investors, regulators, and the public perceive the future of artificial intelligence.