OpenAI has confidentially filed for an initial public offering, marking a major milestone for the company behind ChatGPT and setting the stage for what could become one of the largest technology listings in history.

The move comes just days after rival AI developer Anthropic filed confidentially for its own IPO and as SpaceX prepares for a blockbuster public debut that is expected to test investor appetite for trillion-dollar AI-related companies.

OpenAI, valued at approximately $852 billion following its March fundraising round, said it had submitted a confidential S-1 filing with the U.S. Securities and Exchange Commission. The company stressed that it has not yet determined when it will go public.

“We recently submitted a confidential S-1. We expect it to leak so we’re just announcing it,” OpenAI said in a statement. “We have not decided on timing yet; it may be a while because there are things we want to do that are likely easier as a private company. But it’s a complicated set of tradeoffs and this gives us the option to go public sooner if that ends up being best.”

The confidential filing allows OpenAI to begin discussions with regulators and refine its financial disclosures before publicly releasing detailed financial information.

The move places OpenAI squarely in an increasingly crowded race among AI leaders seeking access to vast pools of investor capital. Last week, Anthropic revealed it had filed confidentially for an IPO shortly after completing a financing round that valued the company at $965 billion, making it one of the most valuable startups in the world.

The near-simultaneous filings highlight the enormous financial demands facing frontier AI developers. While revenue growth across the sector has been explosive, the costs associated with securing advanced chips, building data centers, and running increasingly sophisticated models continue to rise at an extraordinary pace.

OpenAI Chief Financial Officer Sarah Friar signaled earlier this year that the company was preparing itself for life as a public company, telling CNBC that it is “good hygiene” for a business of OpenAI’s scale to “look and feel and act” like a public company.

Industry analysts view the filing as less about immediate fundraising and more about strategic flexibility. By confidentially entering the IPO process now, OpenAI gains the option to move quickly should market conditions remain favorable.

The company is also planning a tender offer that would allow employees to sell shares at the latest valuation. Such transactions have become important for highly valued private technology firms whose employees have accumulated substantial paper wealth but limited liquidity.

The AI Capital Race

OpenAI’s IPO preparations come amid what is rapidly becoming one of the largest capital-raising cycles in technology history. The AI industry is no longer competing primarily on algorithms. Increasingly, competition revolves around access to computing infrastructure.

Companies are spending billions on advanced chips, power generation, data centers, and cloud infrastructure. Investors have begun comparing the current AI buildout to previous eras of railroad construction, telecommunications expansion, and internet infrastructure deployment.

OpenAI has raised more than $180 billion in funding to date. Yet the company continues to consume significant amounts of capital as it trains increasingly advanced models and expands global computing capacity.

Anthropic faces similar pressures. The company recently disclosed annualized revenue of approximately $47 billion in May, up sharply from around $9 billion at the end of 2025, but executives have acknowledged that the cost of building and serving frontier AI models remains enormous.

The backdrop is helping fuel what bankers expect to be an exceptionally active IPO market. SpaceX, which has positioned itself as both a space and AI infrastructure company, is expected to launch one of the largest public offerings ever. The success or failure of that deal could influence how investors evaluate subsequent offerings from OpenAI and Anthropic.

Several Wall Street firms have argued that the market currently possesses sufficient liquidity to absorb these massive offerings. Goldman Sachs CEO David Solomon recently said investors appear to be operating in an environment where “there’s more greed than there is fear,” suggesting capital remains readily available for large AI-related transactions.

Growing Competition

OpenAI’s filing also arrives as competition in artificial intelligence intensifies. The company that ignited the generative AI boom with ChatGPT now faces challenges from Anthropic’s Claude models, Google’s Gemini platform, Meta’s expanding AI efforts, China’s DeepSeek, and Elon Musk’s growing AI ambitions through xAI and SpaceX.

According to SpaceX’s recent IPO filing, OpenAI, Anthropic, and Google are all viewed as key competitors in the race to build advanced AI systems and infrastructure.

OpenAI has responded by concentrating resources on products with the strongest commercial potential. The company has focused on enterprise services and software development tools such as Codex, which competes directly with Anthropic’s Claude Code.

Chief Executive Officer Sam Altman recently described the company’s evolution as entering a “third phase.” According to Altman, OpenAI’s first phase focused on research aimed at artificial general intelligence. The second phase centered on becoming a product company and understanding how users interact with AI tools.

“Now we are entering the third phase,” Altman wrote. “The economy is beginning to reshape around AI. The central question now is how to make advanced AI abundant, affordable, safe, useful, and easy enough for every person and organization to benefit from it.”

That statement offers perhaps the clearest indication yet of how OpenAI intends to position itself ahead of a public listing. Rather than presenting itself solely as an AI research laboratory, the company wants investors to view it as a foundational technology platform capable of reshaping entire industries.

A Defining Test for the AI Boom

OpenAI’s confidential filing represents more than a corporate milestone. It is shaping up to be one of the clearest tests yet of whether public investors are willing to support the immense spending required to build the next generation of AI systems.

For years, private investors have financed the industry’s expansion. Public markets may soon be asked to take over that role. Questions are beginning to emerge about whether corporate spending on AI can continue growing at its current pace. Some large enterprise customers have reported strong productivity gains, while others are still evaluating whether massive AI investments are generating sufficient returns.

Investors will ultimately have to decide whether companies such as OpenAI and Anthropic deserve valuations approaching or exceeding $1 trillion, especially as they continue to burn cash in pursuit of scale.

Steve Eisman, the investor known for his contrarian bet against the U.S. housing market ahead of the 2008 financial crisis, is expressing caution over SpaceX’s upcoming IPO, arguing that the company’s shift toward AI-linked infrastructure is making its business model significantly more capital-intensive and harder to justify at scale.

Speaking on CNBC, Eisman said he is not planning to short the stock when it begins trading, but raised concerns after reviewing SpaceX’s S-1 filing. His central argument focuses on a sharp rise in capital expenditure relative to revenue, which he sees as a structural change in the company’s financial profile.

He pointed to internal data showing that in fiscal 2023, SpaceX’s capital expenditure was about 42% of revenue. In contrast, in the most recent quarter, that figure reportedly surged to 215%, meaning the company is now spending more than twice its revenue on infrastructure investment.

That shift, according to Eisman, reflects a broader strategic transformation rather than a cyclical spike in spending. He argues that SpaceX is increasingly positioning itself not just as a space and satellite operator, but as an AI infrastructure and compute company tied to large-scale data center and processing ambitions.

Eisman’s critique centers on what he sees as a blurring of SpaceX’s core identity. Traditionally, the company’s valuation narrative has rested on two pillars: launch dominance and the Starlink satellite internet network. The newer AI-driven strategy, he argues, is now becoming the dominant driver of capital allocation and future expectations.

He said the company’s future is being increasingly framed around artificial intelligence rather than its established aerospace and communications businesses.

“The entire company is being bet on AI in terms of its future, not on space and not on Starlink,” Eisman said.

That shift places SpaceX in a more competitive and capital-heavy segment of the technology market, where returns depend on massive upfront investment in compute infrastructure, chips, networking systems, and energy capacity.

Eisman also broadened his critique beyond SpaceX, pointing to what he sees as an industry-wide escalation in capital spending driven by artificial intelligence.

He highlighted recent large-scale investment activity, including Alphabet’s massive funding plans, as evidence that major technology firms are moving from an asset-light model toward an increasingly infrastructure-heavy structure.

In his view, this shift is redefining the economics of the AI sector. While generative AI systems and large language models have demonstrated rapid adoption and technological progress, he argued that the underlying products are becoming increasingly interchangeable.

Despite the enormous spending, he said, differentiation between leading AI systems is narrowing, making long-term competitive moats harder to sustain.

“What’s being produced in terms of LLMs and agentic AI is not really differentiable,” he said. “It’s very commoditized.”

That dynamic, he warned, raises the risk that capital-intensive buildouts may not generate proportional returns if pricing power erodes across the industry.

A key theme in Eisman’s remarks is that capital intensity, rather than growth potential, is becoming the defining risk factor for AI-linked companies.

He noted that the scale of investment required for compute infrastructure, data centers, and advanced semiconductor supply chains has expanded rapidly, reshaping the economics of the sector.

This capital cycle is largely being driven by expectations of long-term AI demand rather than proven near-term profitability, creating what he sees as a widening gap between investment levels and monetization certainty. In that context, SpaceX’s IPO narrative is being interpreted not just as a space technology story but as part of a broader AI infrastructure expansion wave.

Eisman’s comments add a note of caution to what is shaping up to be one of the most closely watched public offerings in recent years.

The SpaceX IPO has already attracted significant attention from major banks and institutional investors, with revenue projections and long-term growth scenarios tied heavily to artificial intelligence integration, satellite connectivity expansion, and large-scale compute services.

However, concerns like Eisman’s highlight a growing divide in how investors are assessing the company: between those focused on long-term technological disruption and those scrutinizing the immediate capital requirements needed to sustain that growth trajectory.

While he stopped short of taking a bearish position, his comments imply that enthusiasm around the listing is being met with increasing scrutiny over whether the financial structure supporting the AI expansion cycle is sustainable at current spending levels.