The contest between Anthropic and OpenAI has evolved from academic rivalry into a defining commercial battle for the AI era - one now playing out not just in product launches but in headline-grabbing plans for stock market debuts.
According to people familiar with the matter, OpenAI became aware in late 2022 that Anthropic was developing an AI chatbot. That discovery prompted OpenAI Chief Executive Sam Altman to instruct employees to accelerate a competing project. Within roughly two weeks, OpenAI rolled out ChatGPT on November 30, 2022. The consumer-facing release helped ignite broad interest and investment in generative AI and rapidly altered expectations for how the technology could be used by millions.
That sense of urgency - the need to move faster than a rival - now characterizes both companies' approaches to public listings. Executives at both firms view an initial public offering as a means to define how the market will value frontier AI companies and to cement their chief executives as preeminent industry voices. For months, many advisers expected OpenAI to be first to take steps toward a public listing. OpenAI reportedly told some investors it was targeting an IPO as early as September. Anthropic surprised many by announcing on June 1 that it had made a confidential filing with U.S. regulators; OpenAI followed the next week.
The contest is personal as well as corporate. Anthropic was founded in late 2020 after Dario Amodei and several colleagues left OpenAI, an exit perceived by some at the time as a critique of management style and priorities. The two companies’ leaders - Altman and Amodei - have become focal points in both product competition and public confrontations. Observers within the industry describe the dynamic as fierce and unrelenting, an environment in which every product update from one firm raises expectations of a quick response from the other.
“It’s all-out war between these guys,” said Anastasios Angelopoulos, chief executive of an AI benchmarking and evaluation firm, reflecting how closely releases from one company can presage moves by the other. Both companies declined to comment on the relationship between their leaders.
Wall Street implications
The two listings are large enough that both companies are courting some of the same banks and advisers. That overlap has created complicated relationships for the financial firms involved. Bankers and advisers working with both companies have at times been asked to gather information about the rival’s plans, prompting some banks to erect internal barriers between deal teams to avoid sharing confidential details.
Market participants have described the environment as unusual; it is uncommon for two direct, sizable rivals in the same nascent field to navigate public offerings in such close proximity. The competitive incentives are straightforward: the company that lists first can influence investor expectations around growth, accounting, and valuation benchmarks for emerging AI firms.
Arguments over financial presentation
One prominent area of contention concerns how the two firms present their revenue. The firms use different accounting approaches that yield materially different headline revenue figures, and OpenAI has communicated internally that it believes Anthropic’s chosen method inflates revenue by billions.
At issue is the distinction between gross and net revenue recognition. Anthropic records the full amount customers pay for its AI services as revenue, even though portions of those payments are later directed to cloud partners such as Amazon and Google, according to people familiar with the matter. Anthropic has said it treats itself as the “principal” in those transactions and therefore recognizes gross revenue, viewing cloud partners as distribution channels.
OpenAI, by contrast, reports net revenue after paying its cloud partner, Microsoft. In April, OpenAI’s chief revenue officer sent an internal memo stating publicly-held concerns that Anthropic’s accounting method overstates revenue. The memo was read by people who reviewed it and the communication was described as partly intended to steady OpenAI employees demoralized by Anthropic’s rapid growth.
Industry analysts say the way each company frames its finances could affect investor perceptions. If one firm’s accounting produces substantially higher headline revenue, that could set a precedent for how frontier AI companies are evaluated, an outcome that would advantage the firm with the more generous presentation.
Internal pressures and leadership disputes
The urgency to go public has spilled into senior discussions at OpenAI. Sources say Altman clashed with OpenAI Chief Financial Officer Sarah Friar about whether the firm could meet the obligations of a public listing on an accelerated timetable. According to people familiar with the exchanges, Altman told Friar to either resolve the financing and legal arrangements or hire different bankers and lawyers who could make the abbreviated timeline work. Friar has since indicated to advisers that the company’s leadership is aligned on timing, according to one person close to the situation. After Anthropic’s confidential filing, Altman told CNBC he did not want to rush OpenAI’s debut.
That internal friction follows broader governance drama. In late 2023, OpenAI’s board fired Altman unexpectedly. During the board’s review of options, directors briefly explored the possibility of combining the two labs with Amodei as the leader. In a deposition in a subsequent matter, a former OpenAI executive said that a merger was considered “extremely briefly” before the board pursued other ideas. Although Altman was reinstated within days, the episode left lingering anger among some OpenAI employees.
Product competition and shifting priorities
Product roadmaps at both firms have been shaped by the rivalry. Anthropic trained an early version of its chatbot, Claude, in early 2022 but delayed deploying it publicly while conducting safety research, according to Anthropic. OpenAI had related efforts underway, with some employees working on a “super-assistant” powered by advanced models and others building a chat interface. After rumors in mid-November of Anthropic’s project, OpenAI accelerated its plans and launched ChatGPT at the end of that month.
Anthropic launched Claude a few months later and spent roughly three years narrowing the gap with OpenAI. Sources say that in late 2024 Amodei redirected researchers to develop “reasoning models” after seeing OpenAI’s early strengths in that area. According to several people familiar with the firms’ strategies, the dynamic flipped in late 2025 when Anthropic released a powerful upgrade to its Claude Code tool, prompting OpenAI to shift more resources toward enterprise offerings and its own code-focused product, Codex.
Public spats and growing visibility
Relations between the two labs soured further following the 2023 board episode. Public tensions have included Altman criticizing Anthropic’s Super Bowl advertising as “deceptive” for its representation of OpenAI plans for ads on ChatGPT. In March, Amodei accused Altman of exploiting Anthropic’s dispute with a Pentagon contract to advance OpenAI’s position. At an AI event in India in February, Prime Minister Narendra Modi asked executives on stage to join hands in a symbolic gesture of unity; video from the event showed Altman and Amodei standing together but declining to take the gesture.
Those public exchanges underscore a rivalry that extends beyond engineering choices into how each company cultivates public and political narratives about safety, commercial strategy and market positioning.
Why the first IPO matters
One clear reason both companies are pressing to be first to market is the ability to shape investor expectations around a frontier AI firm’s financial presentation and long-term growth trajectory. Analysts and advisers say the first public comparison sets benchmarks for valuation, accounting norms and disclosure standards within a nascent industry where standardization is not yet established. This is particularly consequential for sectors that will rely on AI infrastructure and enterprise software, as well as the cloud providers that host large models.
For banks and advisers, the overlapping mandates present practical challenges in preserving client confidentiality and avoiding conflicts of interest. Several institutions have responded by separating teams internally, a measure intended to limit cross-deal knowledge and ensure compliance with client protections.
What remains uncertain
Despite the public filings and talk of timetables, major questions remain about exactly how and when either company will complete a public offering and how investors will compare their financial statements, product roadmaps and safety commitments. Company leaders have been tight-lipped on many specifics; both firms declined to comment on the rivalry between CEOs when asked.
The rivalry between Anthropic and OpenAI has already influenced the pace of product releases, generated debate over accounting practices, and introduced governance strains. As the two companies move closer to public markets, investors, bankers and enterprise customers will be watching how the competition shapes disclosures, valuation norms, and the public discourse around responsible AI deployment.