Anthropic’s accelerated IPO preparations, including its June confidential S-1 filing and targeted mid-November 2026 listing window before Thanksgiving, stand as the main driver behind the 95.5% market-implied odds favoring it to reach public markets ahead of OpenAI. Recent Bloomberg and Reuters reporting confirms Anthropic is advancing marketing efforts while disclosing substantial revenue growth alongside heavy compute commitments, positioning the Claude developer for a potential $2 trillion debut. In contrast, OpenAI CEO Sam Altman explicitly ruled out a 2026 IPO in September interviews, citing the need to address AI safety and alignment concerns first, with the company instead pursuing additional private funding rounds. Trader consensus reflects these verified timelines, though modest uncertainty persists around possible regulatory reviews, market volatility, or shifts in OpenAI’s safety milestones that could compress or extend the gap.