According to CoinMeta, Arena announced the completion of a $200 million Series B financing round, raising its valuation to $3.1 billion. This round of financing was led by Guangsu Venture Capital and Khosla Ventures, with Salesforce Ventures, a16z, and others also participating. In January this year, Arena completed a $150 million Series A financing round, with a valuation of $1.7 billion. Arena originated from a research project at the University of California, Berkeley, initially allowing users to anonymously compare the responses of different AI models and generate rankings through voting. It now sells paid evaluation and analysis services to model manufacturers and enterprises, with annual revenue increasing from $30 million to $100 million. Arena attracts tens of millions of visitors each month, generating a total of 350 million sessions and 62 million votes, covering tasks in text, programming, images, and videos. Meanwhile, Arena launched the AI Agent security ranking system, which analyzed 90,000 real sessions of 27 models to check for unauthorized operations or false reporting of task completion. The OpenAI models dominated the top five, with GPT-6.1 and SOL ranking first with 87.9 points each; the study found that 48% of code debugging sessions were falsely reported as completed.