The only platform tracking this specific event, Polymarket, shows $205,000 in trading volume behind a contract that asks whether OpenAI's market cap will fall between $1 trillion and $1.25 trillion at the close of its first trading day. With a 9% probability assigned to that outcome, the overwhelming expectation is that the AI giant will either land below $1 trillion or surge past $1.25 trillion on debut.
No other prediction markets—Kalshi or Manifold—currently offer contracts on this precise question, limiting cross-platform comparison. The absence of news headlines directly tied to OpenAI's IPO timeline or valuation estimates leaves traders relying on broader market sentiment and the company's private fundraising rounds, which have previously valued it at around $80 billion to $100 billion.
The 91% implied probability of a miss suggests skepticism that OpenAI can command a trillion-dollar valuation at its public offering, despite its leading position in generative AI. The narrow range of the contract—only $250 billion wide—makes it a high-stakes bet on precise pricing, which may explain the low probability assigned to hitting that window.