CONDITIONAL ON OpenAI NOT having released a step-change model before IPO: What will OpenAI's market capitalization be 90 days after its IPO?

The condition that OpenAI does not release a step-change model before its IPO mostly describes a continuation of the current status quo. As of mid-October 2026, no OpenAI model meets the criteria for a dominant benchmark lead, with Anthropic's Claude Opus 5.5 leading the Artificial Analysis index and OpenAI having canceled the release of GPT-6.1 Astra over safety scope concerns https://www.cnbc.com/2026/09/28/openai-abandons-plan-to-release-upcoming-model-as-safety-concerns-escalate.html. Under this scenario, OpenAI enters the public market as a strong but non-dominant player relative to Anthropic, lacking a breakthrough-driven valuation premium.

Timing for an IPO has likely shifted to 2027 or 2028. CEO Sam Altman has ruled out a 2026 debut https://www.techzine.eu/news/analytics/144257/altman-postpones-openai-ipo-due-to-ai-risks/, and the repayment of SoftBank's bridge loan removes the pressure of an early 2027 deadline. At the same time, top-line growth remains explosive. The annualized revenue run rate approached $50B in September and is projected to reach $70B or more by year-end https://thenextweb.com/news/openai-revenue-70bn-year-end-50bn-september https://thenextweb.com/news/openai-revenue-70bn-year-end-50bn-september. However, this growth comes at a steep cost, evidenced by a $12.3B Q2 operating loss on $6.7B of revenue https://finance.yahoo.com/technology/article/openais-annualized-revenue-20-billion-lower-than-prior-investor-estimates-174058048.html. These mixed fundamentals, together with the extended runway for revenue growth before a likely 2027 or 2028 IPO, anchor the median market cap estimate near $1.5T, modestly above but closely aligned with reported private talks to raise new capital at a $1.4T pre-money valuation https://thenextweb.com/news/openai-revenue-70bn-year-end-50bn-september OpenAI reportedly in talks to raise $30B round at $1.4T ....

Anthropic’s impending IPO will serve as the critical comparative benchmark. Anthropic’s Q2 revenue surpassed OpenAI's, and it operates profitably on an adjusted basis Anthropic Q3 revenue climbs to $16.8 billion: Report https://www.reuters.com/business/finance/anthropics-q3-revenue-surges-45-nearly-17-billion-2026-10-14/. While the market has anticipated a valuation around $2T for Anthropic Anthropic Pushes Its IPO to November as Investors Eye a ... https://www.reuters.com/business/finance/anthropics-q3-revenue-surges-45-nearly-17-billion-2026-10-14/, broader concerns regarding AI capital expenditures have led some investors to push back toward a $1.5T valuation Some investors push Anthropic to cut IPO valuation to $1.5 ... CoreWeave's slump spotlights growing burden of debt .... Given OpenAI's heavy losses and lack of a definitive benchmark lead, it is reasonable to apply a discount to its public multiples relative to Anthropic. Furthermore, historical mega-IPOs like SpaceX demonstrate that while initial trading days can see massive volatility, valuations 90 days out often settle relatively close to the IPO listing price Initial public offering of SpaceX Space Exploration Technologies (SPCX) Market Cap & Net ....

The distribution reflects both the expected listing constraints and compounding revenue trajectories, while remaining consistent with the unconditional first-day valuation . Altman’s reported insistence on a $1T valuation acts as a soft floor for the initial listing price Sam Altman Is Pushing for a $1 Trillion IPO Valuation ... Altman Confirms OpenAI Won't IPO Until 2027. However, a post-listing dip, a broader AI sector correction, or a weak Anthropic debut justifies a 10th percentile estimate of $0.9T and a 25th percentile of $1.2T. Conversely, the upper bounds (a 75th percentile of $1.95T and a 90th percentile of $2.5T) account for continued aggressive enterprise adoption https://thenextweb.com/news/openai-revenue-70bn-year-end-50bn-september and the possibility that the IPO slips into 2028. By then, revenue would have compounded significantly, supporting a much larger market capitalization even without a step-change technological leap.