The competition between OpenAI and Anthropic has become the defining force in artificial intelligence development, with the two companies now racing toward initial public offerings (IPOs) that could reshape how investors value AI companies and establish which CEO becomes the leading voice of the industry. Anthropic filed confidentially with U.S. regulators on June 1, beating OpenAI to the punch after months of speculation about which company would go public first.

The rivalry's roots run deep, stretching back to late 2022 when OpenAI learned that Anthropic was developing an AI-powered chatbot. In response, OpenAI CEO Sam Altman directed employees to fast-track a competing product, according to four people familiar with the matter. Two weeks later, OpenAI released ChatGPT on November 30, 2022, launching what would become the fastest-growing consumer application in history.

What started as a two-week sprint to beat a rival has evolved into a broader competitive dynamic that influences how quickly AI tools are released, what features they include, and ultimately how people interact with the technology daily. The stakes are enormous: OpenAI is targeting an IPO valuation around $1 trillion, according to Reuters reporting cited in the source material.

Why Are These Two Companies in Such Direct Competition?

The feud between Altman and Anthropic CEO Dario Amodei, a former OpenAI researcher who helped develop the core technology behind ChatGPT, has become personal and public. Amodei left OpenAI in late 2020 to create Anthropic, a move many saw as a rebuke of Altman's approach to AI development. While Anthropic trained its Claude chatbot in early 2022, the company held it back from public deployment to conduct safety research instead, giving OpenAI time to capture the market.

The tension between the two leaders has only intensified. In February, Altman slammed Anthropic's Super Bowl advertisements as "deceptive" for misrepresenting OpenAI's plans to sell ads on ChatGPT. Later in March, Amodei accused Altman of leveraging Anthropic's dispute with the Pentagon to help OpenAI. At an AI summit in India in February, when Indian Prime Minister Narendra Modi encouraged all tech executives on stage to join hands in a show of unity, a viral video captured Altman and Amodei, standing next to one another, refusing to do so.

How Are the Companies Competing on Product Development?

The competitive dynamic has created a pattern of rapid-fire releases and feature updates. Around late 2024, Amodei redirected Anthropic researchers to focus on reasoning models after seeing OpenAI's early success in that area, according to three people familiar with the matter. The dynamic flipped in late 2025 when Anthropic released a powerful update to its Claude Code tool. OpenAI, which generates much of its revenue from consumers paying for ChatGPT, has since redoubled its focus on enterprise software and pulled more resources into its own coding product, Codex.

"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," said Anastasios Angelopoulos, CEO of Arena, a top AI benchmarking and evaluation company.

Anastasios Angelopoulos, CEO at Arena

This competitive pressure has accelerated innovation across the industry. Anthropic spent about three years catching up to OpenAI after Claude's launch, but the gap has narrowed significantly. The two companies are now leapfrogging each other on key capabilities, with each release from one company prompting a rapid response from the other.

What's at Stake in the IPO Race?

Beyond the prestige of going public first, the IPO race involves a critical battle over financial reporting standards. OpenAI has told investors and employees that Anthropic's preferred accounting method overstates its revenue by billions of dollars. In April, OpenAI's chief revenue officer, Denise Dresser, told employees that OpenAI considers Anthropic's financials inflated, according to a company memo reviewed by Reuters.

The accounting disagreement centers on how each company recognizes revenue. Anthropic books the full amount that customers pay for its AI services as revenue, even though part of that sum is later routed to partners such as Amazon and Google. OpenAI uses a different method, reporting only net revenue after paying its partner, Microsoft. Anthropic argues it follows established accounting practices and recognizes gross revenue because it is the "principal" in the transaction, while its cloud partners are distribution channels.

This difference matters enormously for investors. According to Gil Luria, an analyst at D.A. Davidson, "One reason for Anthropic to try to beat OpenAI out to the public market is that they will get to set the agenda for how a frontier model reports financials and do so in a way that is favorable to their financial model".

How Are Banks Managing the Conflict of Interest?

The IPO race has created unusual challenges for investment banks working with both companies. It's rare for two such big direct rivals to raise capital at the same time, and the IPOs will be so large that they are by necessity turning to some of the same banks for help. Bankers and other advisers are navigating increasingly complex relationships with both OpenAI and Anthropic, with executives at both companies pressing their IPO advisers for insight into the rival's plans.

To prevent information leaks, some banks working with both companies have erected internal barriers between deal teams. This separation is critical because the stakes are so high: the IPO that goes public first will likely set the valuation benchmark for the entire frontier AI industry.

Steps to Understanding the AI IPO Competition

• Timeline Context: OpenAI released ChatGPT in November 2022 after a two-week development sprint, while Anthropic launched Claude months later and spent about three years catching up in capabilities.
• Financial Reporting Difference: Anthropic reports gross revenue from customers, while OpenAI reports net revenue after paying Microsoft, creating a significant difference in how investors will evaluate the companies.
• IPO Strategy: Anthropic filed confidentially in June, beating OpenAI to the punch, which allows Anthropic to potentially set the financial reporting standard that investors will use to evaluate both companies.
• Leadership Tension: The rivalry between Sam Altman and Dario Amodei has become increasingly public, with the two refusing to participate in a show of unity at an AI summit in India in February.
• Banking Challenges: Investment banks working with both companies must maintain internal barriers between deal teams to prevent information leaks about each company's IPO plans and valuations.

The tension between Altman and Amodei has also created internal challenges at OpenAI. Altman recently clashed with CFO Sarah Friar over whether the company could meet the obligations required for a public listing on such a compressed timeline, according to three people familiar with the matter. Altman reportedly told her to figure it out or hire different bankers and lawyers who could pull it off. Friar has since told advisers that the company's leadership is aligned on timing.

Relations between the two companies deteriorated significantly after Altman was unexpectedly fired by OpenAI's board in late 2023. As the board cast about for options, directors briefly spoke with Amodei about merging the two labs under his leadership. In a recent deposition, one former OpenAI executive said the idea was considered "extremely briefly" before the board moved on to other ideas. Even so, news of the proposal infuriated many OpenAI employees, and the anger persisted even after Altman was reinstated within days.

The IPO race represents more than just a financial milestone for these two companies. It will establish how investors value frontier AI companies, set accounting standards for the industry, and determine which CEO becomes the dominant voice in shaping how artificial intelligence develops and integrates into society. As the two companies race toward their public debuts, the competitive pressure that has driven innovation over the past few years shows no signs of slowing down.