OpenAI CEO Sam Altman stated in September 2026 that the company would not pursue an IPO this year, prioritizing AI safety and alignment work on its large language models over a public listing amid rapid capability advances. This explicit delay to 2027, combined with Anthropic’s confidential SEC filing in June and active preparations for a November 2026 debut at a potential $2 trillion valuation, has driven the market-implied odds strongly toward Anthropic. Traders cite Anthropic’s revenue trajectory exceeding $100 billion annualized and completed regulatory steps as key momentum. Realistic scenarios that could still shift the outcome include last-minute market volatility delaying Anthropic’s roadshow, unexpected regulatory hurdles, or an abrupt reversal in OpenAI’s safety timeline, though recent statements make the latter unlikely before year-end.