OpenAI's commanding lead in the trader consensus for second-largest private company stems from its rapid valuation growth amid surging demand for large language models and generative AI capabilities. A March 2026 round valued it at $852 billion with $122 billion raised, followed by ongoing talks for a $1.4 trillion pre-money round and annualized revenue nearing $70 billion. This momentum, backed by investors including SoftBank and Nvidia, has kept OpenAI close behind Anthropic's $965 billion mark while far outpacing fintech names like Revolut at $115 billion and Stripe at $159 billion. Key near-term catalysts include funding closure and any updates on 2027 IPO plans before October-end resolution.