Arena (formerly LMArena / LMSYS Chatbot Arena) announced October 8, 2026 a 3.1 billion valuation, co-led by Lightspeed Venture Partners and Khosla Ventures. The company reported exceeding 30 million at its January 2026 Series A ($1.7 billion post-money). Arena launched an Alignment Index measuring real-world value deviation and expanded commercial AI Evaluations beyond crowdsourced public leaderboards.