Anthropic’s planned November IPO at a targeted $1.8–2 trillion valuation, versus OpenAI’s deferral of its public debut until 2027, anchors the 92% market-implied probability that Anthropic will hold the higher valuation on December 31. Anthropic’s May 2026 Series H priced the company at $965 billion with a $65 billion annualized revenue run rate, and recent reports show continued Q3 momentum alongside strong enterprise adoption of Claude models. OpenAI’s latest $852 billion private round and $50 billion September run rate trail on both metrics, though management projects a $70 billion year-end target ahead of a potential $1.4 trillion pre-IPO raise. Key swing factors include final IPO pricing outcomes and any material revenue revisions before year-end.