AI model evaluation platform Arena has secured $200 million in new funding at a $3.1 billion valuation, nearly doubling its $1.7 billion valuation from January. Lightspeed Venture Partners and Khosla Ventures led the round, with participation from Salesforce Ventures and Dell Technologies Capital. Arena originated from the Chatbot Arena research project at the University of California, Berkeley, and is widely recognized for its public large model leaderboard. The platform reported annualized revenue of $100 million as of June this year.