**Alphabet's market capitalization of approximately $4.3 trillion as of mid-October 2026 substantially exceeds the combined private valuations of OpenAI and Anthropic, supporting the 81% market-implied probability that Google maintains the higher valuation through December 31.** Alphabet benefits from diversified revenue streams, including advertising and cloud services exceeding $400 billion annually, alongside established public-market liquidity and analyst targets around $420 per share. In contrast, OpenAI's most recent confirmed post-money valuation stands at $852 billion from its March 2026 round, with secondary marks implying $967 billion to $1.2 trillion and preliminary talks for a $30 billion raise at roughly $1.4 trillion pre-money. Anthropic reached $965 billion in its May 2026 Series H, with secondary indications up to $1.39 trillion and IPO aspirations discussed near $2 trillion. Combined, even optimistic marks place the pair below $3.5 trillion—well short of Alphabet's scale—while their rapid revenue run rates (OpenAI nearing $70 billion annualized; Anthropic exceeding $65 billion and targeting over $100 billion) reflect growth from a far smaller base. Key near-term catalysts include Alphabet's October 28 earnings release and potential regulatory or IPO milestones for the AI labs, though OpenAI has deferred its public debut beyond 2026. Traders price in the persistent gap driven by public-market fundamentals versus private funding dynamics, with limited scope for convergence by year-end absent extraordinary shifts.