Arena, the AI leaderboard everyone uses, is now a $100M business

Elsewhere, Handshake’s gross annualized revenue from AI training has nearly doubled since January, climbing from $550 million to nearly $1 billion, The Information reported in April. Mercor’s annualized revenue also topped $1 billion earlier this year, up from $500 million last September, according to The Information.

Arena ranks models on a variety of tasks such as text, coding, vision, and image generation, as well as complex, long-running workflows through its recently introduced Agent Mode.

Along with Angelopoulos (pictured left), Arena was co-founded by fellow UC Berkeley postdoctoral student Wei-Lin Chiang (pictured center), who serves as the startup’s CTO. The startup was also co-founded by Ion Stoica (pictured right), the renowned UC Berkeley professor and Databricks co-founder who advised the project before it incorporated as a company in April 2025.

Arena has raised a total of $250 million from investors including Felicis, Andreessen Horowitz, The House Fund, LDVP, Kleiner Perkins, Lightspeed Venture Partners, Laude Ventures, and UC Investments.