Anthropic's active preparations for a mid-November 2026 listing, including confidential SEC filings, a detailed prospectus, and roadshow marketing targeted for the week of November 9, form the core driver behind the 96.5% market-implied odds favoring it to IPO ahead of OpenAI. Trader consensus reflects Anthropic's revenue trajectory—annualized run rate exceeding $65 billion with projections toward $110 billion—alongside competitive positioning in large language models like Claude, while OpenAI CEO Sam Altman has publicly ruled out any 2026 debut to prioritize AI safety and alignment work, opting instead for a $30 billion private bridge round at roughly $1.4 trillion valuation. Potential swing factors include last-minute regulatory hurdles or market volatility that could slip Anthropic's timeline, though OpenAI's explicit 2027 commitment makes reversal improbable in the near term.