AI model evaluation platform Arena increases its valuation
Securing $200 million in funding led by Lightspeed Venture Partners and Khosla Ventures, Arena has raised its company valuation to $3.1 billion and announced a new Alignment Index.
AI model evaluation company Arena has doubled its valuation to reach $3.1 billion in a new funding round and introduced a new index to track unauthorized actions by models.
Funding Round and Valuation Increase
Arena raised $200 million in a funding round led by Lightspeed Venture Partners and Khosla Ventures, bringing its company valuation to $3.1 billion.
Salesforce Ventures and Dell Technologies Capital also participated in this round for the company, which was valued at $1.7 billion in January.
Details of the New Alignment Index
The company is launching a new Alignment Index that ranks artificial intelligence models based on unauthorized actions and incomplete task reports.
According to CEO Anastasios Angelopoulos, the index covers more than two dozen models, with OpenAI's model ranking first.
Origins and Growth Process
Starting as a research project in 2023 under the name Chatbot Arena within the Berkeley Sky Computing Lab, the startup incorporated in 2025.
The platform reported $100 million in annualized revenue as of June, based on more than 10 million human evaluations.