Anthropic’s active preparations for a mid-November 2026 IPO, including its recent prospectus filing and revenue run-rate exceeding $65 billion, drive the 96.5% market-implied probability that it will list before OpenAI. OpenAI CEO Sam Altman has explicitly ruled out a 2026 debut, citing the need to address AI safety and alignment for frontier large language models before facing public-market pressures, and the company is instead pursuing a large private funding round. This timeline gap reflects Anthropic’s faster regulatory and financial readiness amid strong enterprise adoption of its Claude models. While near-term catalysts like U.S. midterm elections or market volatility could still delay Anthropic’s roadshow, OpenAI would require a significant reversal of its stated safety priorities to close the gap before year-end.