Anthropic's active IPO preparations, including its June 2026 confidential SEC filing and targeted November listing window after recent timeline adjustments, drive the overwhelming 96.5% market-implied odds that it will reach public markets ahead of OpenAI. Recent reports confirm Anthropic is advancing marketing efforts and expects a valuation near $2 trillion, supported by surging revenue run rates exceeding $65 billion annualized. In contrast, OpenAI CEO Sam Altman has publicly ruled out a 2026 IPO, citing priorities around AI safety, model alignment, and regulatory considerations, with the company instead pursuing private funding rounds at roughly $1.4 trillion. While strong consensus reflects these verified developments, realistic shifts could arise from further Anthropic delays due to market conditions or regulatory reviews, or an unexpected acceleration in OpenAI's safety milestones that revives its timeline.