After competitors Anthropic and SpaceX successively initiated their listing processes, AI giant OpenAI has officially joined the race for a mega IPO. On Monday local time, OpenAI announced that it had confidentially submitted a draft S-1 registration statement to the U.S. Securities and Exchange Commission, while also emphasizing that a specific timeline for the listing has not yet been finalized.
According to sources familiar with the matter, OpenAI is collaborating with Goldman Sachs and Morgan Stanley to prepare for the listing. If all proceeds smoothly, the company could potentially go public as early as this fall. Prior to the formal listing, OpenAI also plans to launch a tender offer for employees in the coming weeks, allowing them to sell some of their shares at the valuation from its latest funding round completed in March—$852 billion. To date, OpenAI has raised over $180 billion in cumulative funding. Notably, a California court last month dismissed Elon Musk’s lawsuit against OpenAI and its CEO Sam Altman, removing a major uncertainty from OpenAI’s path to an IPO.
OpenAI is not alone. A week ago, its direct AI competitor Anthropic announced that it had confidentially filed an IPO application with the SEC, with its valuation surging to $965 billion in its most recent private funding round. An even more immediate competitive pressure comes from Musk’s SpaceX, which filed its IPO registration statement in mid-May, targeting a market debut as early as June 12. According to compiled data, SpaceX’s IPO valuation is estimated at approximately $1.77 trillion, while Anthropic’s IPO valuation is expected to reach the trillion-dollar level. Combined with the offering scale of OpenAI, the total new market capitalization injected by the three companies could approach $4 trillion.
Faced with such massive supply, whether the U.S. stock market can smoothly absorb it has become a key concern for traders. In the short term, as noted by the chief strategist at Interactive Brokers, newly listed companies are quickly added to benchmark indices like the S&P 500, and ETFs tracking those indices will be forced to buy in. However, analysts point out that SpaceX’s initial weighting in the S&P 500 may be only around 0.1%, so passive short-term support may be limited. What the market truly fears is the selling pressure after IPO lock-up periods expire. Taking SpaceX as an example, the free float ratio at the time of listing is only about 4%, but according to the lock-up expiration schedule, insiders will be allowed to sell 20% of their shares after the first quarterly earnings report. Historical data also sounds a warning: research by a University of Florida professor shows that from 1980 to 2024, U.S. listed companies underperformed the broader market by an average of 20 percentage points in the three years following their IPOs. Moreover, SpaceX’s valuation of nearly $1.8 trillion already exceeds its revenue by more than 90 times, placing heavy pressure on long-term valuation normalization.
