Anthropic’s May 2026 Series H round at a $965 billion post-money valuation, which eclipsed OpenAI’s $852 billion March mark, remains the dominant driver of market-implied odds for the second-largest private company by month-end. Secondary-market trading has since pushed Anthropic above $1.2 trillion, reinforcing its position as the clear leader and leaving OpenAI as the consensus runner-up at 62.5 percent implied probability. Traders see limited near-term catalysts before August 31 that could reorder the ranking, with no comparable late-stage raises reported for Stripe, Databricks, or other contenders. OpenAI’s ongoing IPO preparations and revenue trajectory add minor uncertainty, yet current private valuations and capital inflows continue to anchor the market’s view that Anthropic will hold the top spot through the resolution window.