Anthropic’s confidential S-1 filing on June 1, 2026, combined with banker discussions and a reported October 2026 target date, has driven strong trader consensus that it will reach public markets ahead of OpenAI. The company’s recent $65 billion Series H round at a $965 billion valuation and accelerating revenue run-rate further support readiness for a fall listing once SEC review concludes. In contrast, OpenAI’s own confidential filing in late May has been followed by reports that it is now leaning toward a 2027 debut after initially targeting late 2026, reflecting internal deliberations and shifting market-conditions considerations. These timelines, rather than valuation gaps alone, explain the 89.5% implied probability for Anthropic, with the primary near-term catalyst remaining any public S-1 release or definitive pricing window confirmation for either large language model developer.