OpenAI confidentially files for IPO as AI listings accelerate

OpenAI has confidentially filed for a U.S. initial public offering as major AI companies move toward public markets. The ChatGPT maker did not disclose the size or terms of the planned listing.

Reports said the company may seek a valuation of up to $1 trillion. The filing comes as Anthropic and SpaceX also pursue large stock market debuts.

OpenAI targets major public market debut

According to the report, OpenAI could complete its market debut as early as September. A $1 trillion valuation would place the company among the largest IPO candidates in recent years. The filing follows a period of rapid revenue growth and rising demand for AI tools. Investors have continued seeking public exposure to artificial intelligence companies. OpenAI has become one of the most closely tracked firms in the sector.

OpenAI said earlier this year that it was raising $110 billion at an $840 billion valuation. Its backers included SoftBank, Amazon, and Nvidia, according to the report. The company also disclosed more than 900 million weekly ChatGPT users. It said ChatGPT had more than 50 million consumer subscribers. Those figures came before the confidential IPO filing.

In March, OpenAI said it generated $2 billion in monthly revenue. The company also said its growth rate exceeded earlier internet and mobile-era companies. At the end of 2024, OpenAI generated about $1 billion in quarterly revenue. The latest revenue figures show a sharp increase from that level. The company has not released new IPO terms.

Anthropic and SpaceX join IPO race

Anthropic also confidentially filed for a U.S. IPO on Monday. The company has become one of OpenAI’s largest competitors through its Claude AI products. Its Claude Code tool has gained demand from software developers. Anthropic also markets advanced models for code review and vulnerability research. The company recently raised $65 billion at a $965 billion valuation.

SpaceX has also filed for an IPO that could become the largest in history. Reports said Elon Musk’s company seeks a $75 billion offering. The deal would value SpaceX at about $1.75 trillion if completed. Prediction markets had expected OpenAI to file before Anthropic. Both AI filings now add pressure to the U.S. IPO calendar.

Bankers cited in the report said large AI offerings could affect smaller listings. They said major deals may absorb capital from other planned IPOs. However, the filings could also increase activity in the U.S. IPO market. Investors are now weighing large private AI companies against public market demand. The offerings will test appetite for high-growth technology stocks.

Microsoft deal and Musk lawsuit shape backdrop

OpenAI’s IPO filing follows changes to its partnership with Microsoft. Microsoft has invested about $13 billion in OpenAI since 2019. That relationship helped support OpenAI’s growth and Azure cloud demand. OpenAI later renegotiated the partnership to pursue deals with Amazon and Google. The company has continued seeking capital for advanced AI development.

OpenAI began in 2015 as a nonprofit research organization. It created a for-profit arm in 2019 to fund expensive AI development. Its structure drew scrutiny in 2023 after CEO Sam Altman briefly lost his role. Employees pushed back, and Altman returned days later. In December 2024, OpenAI proposed a public benefit corporation structure.

Elon Musk later sued OpenAI and accused the company of moving away from its original mission. A U.S. jury ruled against Musk in May. The verdict found OpenAI not liable to Musk over those claims. The ruling removed a legal issue before the IPO filing. OpenAI has not publicly commented on final listing timing.