Traders assign a 99% probability to no Anthropic IPO by June 30, 2026, because the AI lab’s earliest credible listing window remains October 2026 or later in Q4. Recent private funding rounds underscore the preference for staying private: a $30 billion Series G closed in February at a $380 billion valuation, followed by a $65 billion Series H in late May that lifted the post-money valuation to $965 billion and pushed annualized revenue run-rate above $47 billion. No S-1 filing has been submitted, and executives continue to prioritize compute-scale partnerships with Amazon and Google alongside internal model development. An IPO this close would require an abrupt acceleration of regulatory, accounting, and roadshow timelines that have not materialized. The only realistic path to an earlier close would be an unforeseen strategic pivot or regulatory catalyst that compresses the standard six-to-nine-month public-company preparation process, an outcome markets currently price as remote.