Will OpenAI or Anthropic IPO first?

The current reporting base strongly favors Anthropic as the earlier IPO candidate. Multiple recent reports point to Anthropic preparing to publish its prospectus in September 2026 and potentially list in late September or early October, while OpenAI’s timeline has shifted later, with CFO guidance and Reuters-linked reporting suggesting 2027 is now the more plausible public-market window. Confidential filings matter because they show both companies are moving through the process, but the key variable here is not who filed first privately; it is who actually reaches pricing and listing first, and the current evidence leans toward Anthropic.

OpenAI still has a path to surprise on the upside, especially if business conditions improve or management decides to accelerate the offering after the confidential S-1. That said, the latest signal is directional rather than tentative: the earlier September 2026 OpenAI chatter appears to have weakened, and there are repeated references to delay rather than advancement. If OpenAI is publicly telling staff to expect 2027, that is a meaningful anchor, because companies usually do not set expectations that far out unless the earlier window has become less realistic.

Against that backdrop, a 97% market price for OpenAI-first looks much too high unless the contract definition is different from the plain reading of the question. If the market is indeed asking which company will IPO first, then it seems to be overweighting the earlier OpenAI rumors and underweighting the more recent Anthropic timing. The most likely explanation for the mispricing is either stale information, confusion about the contract wording, or simple momentum in a thinly questioned market that has not fully incorporated the newer reporting.