San Francisco, June 3, 2026, 06:02 PDT
OpenAI’s pursuit of a U.S. IPO now runs into a stiffer public market challenge: Anthropic has filed confidentially for its own listing, just as fresh data shows ChatGPT topping 1 billion monthly active app users.
The question for investors right now is less about user counts and more about whether the leading artificial intelligence firms can convert their expensive computing infrastructure into lasting earnings. OpenAI, for its part, is reportedly gearing up to file confidentially for a U.S. IPO within weeks, eyeing a possible listing as soon as September, according to Reuters, which cited sources familiar with the situation.
By filing for an IPO confidentially, a company can send draft registration documents to U.S. regulators without immediately revealing its prospectus. If OpenAI goes this route, it signals progress toward what could be one of the most anticipated stock market debuts in recent memory. Previous reporting from Reuters has suggested OpenAI’s valuation could reach as high as $1 trillion.
ChatGPT has surged past 1 billion monthly active app users worldwide as of May, according to estimates from Sensor Tower. That’s the fastest any app has reached the milestone. Sensor Tower’s data also puts Claude, developed by Anthropic, at 56 million monthly active app users so far this quarter—though it’s growing faster year-on-year than ChatGPT.
Anthropic is out of the gate first. The company announced Monday it has confidentially submitted paperwork for a U.S. IPO, beating OpenAI to the punch in letting public markets gauge the value of top-tier AI players. Details on the deal’s size and terms remain under wraps.
OpenAI stands out for its sheer size, even in Silicon Valley. In March, the company announced a $122 billion funding round, putting its post-money valuation at $852 billion. Amazon, Nvidia, SoftBank, and Microsoft all participated. OpenAI also reported more than 900 million weekly active ChatGPT users and over 50 million paying subscribers.
It’s not just about OpenAI anymore. According to Reuters, SpaceX is shooting for a $75 billion IPO, targeting a massive $1.75 trillion valuation—potentially the biggest yet. OpenAI and Anthropic are also said to be queuing up, each eyeing their own headline-making debuts and ready to chase after overlapping pools of investor money.
“With that legal overhang out of the way, OpenAI just cleared a key roadblock to going public. That probably sped up their plans,” Kat Liu, vice president at IPOX, told Reuters after the court tossed Elon Musk’s suit against the company. Liu added: portfolio managers will now have to weigh OpenAI against SpaceX directly, since both could file at the same time. Reuters
Goldman Sachs CEO David Solomon on Tuesday said there’s “enough capital” in the system to handle the wave of mega-IPOs he expects. Still, he warned the market feels tipped toward “more greed than there is fear” right now. That kind of mood can disappear quickly if companies miss on growth or margins. Reuters
OpenAI faces a key uncertainty: even massive scale might not quiet critics. Training AI models demands giant data centers crammed with cutting-edge chips, a setup that drives up costs fast. Investors, watching those expenses climb, are expected to demand much sharper proof that revenue growth isn’t lagging behind the burn rate.
Competition is getting fiercer. Karen Kwok at Reuters Breakingviews flagged that both OpenAI and Anthropic face the same stubborn hurdle: limited computing power, and there’s no easy workaround. With Anthropic’s valuation climbing, Kwok pointed out that snapping up infrastructure firms could become more attractive—assuming public investors keep paying up.
OpenAI has previously looked to expand its future shareholder base ahead of a potential listing. Back in April, Chief Financial Officer Sarah Friar told CNBC the company was planning to earmark some IPO shares for retail investors, describing it as “good hygiene” for a company of OpenAI’s scale to “look and feel and act … like a public company.” Reuters
Forget the next boast; it’s the coming document that will really count. Once OpenAI files publicly, investors will finally see the numbers that matter: revenue quality, losses, compute commitments, customer mix, and governance. That’s the first real window into the financial guts of the most scrutinized private AI firm out there.
