Arena raises $200M in Series B, launches Alignment Index

a16z: a16z is a venture capital firm with extensive investments in AI, crypto, and internet technologies. It continued its support as an existing investor in Arena's Series B round. The participation reinforces commitment to independent evaluation of AI capabilities and alignment. Arena: Arena is an AI evaluation platform focused on measuring real-world capabilities and alignment of AI agents through community-driven benchmarks and traces. It has evolved from human preference evaluations to assessing agentic workflows in areas like coding and analysis. The company is releasing its Alignment Index today while securing new funding to expand safety signals and agentic capabilities. AMP PBC: AMP PBC is an investment firm participating in technology and AI ventures. It joined as an existing investor in Arena's Series B, supporting the Alignment Index release. The firm contributes to scaling efforts in measuring AI alignment through real-world data. Felicis: Felicis is a venture capital firm investing in early-stage technology companies, particularly in AI and consumer software. It remains an existing backer in Arena's latest funding round. The ongoing involvement aids Arena's development of benchmarks for agent safety and real-world performance. 01 Advisors: 01 Advisors is a venture firm specializing in investments in AI and software companies. It joined Arena's Series B round, contributing to the platform's expansion of alignment and capability measurements. The firm supports Arena's role as an independent evaluator of frontier AI models. QuantumLight: QuantumLight is a venture capital firm focused on AI and deep technology investments. It participated as an existing investor in the Series B round for Arena. The support enables further work on safety signals and agentic AI evaluation. The House Fund: The House Fund invests in early-stage companies in technology and AI. It continued backing Arena through the Series B round alongside other investors. The involvement helps sustain the platform's growth in community-driven AI benchmarks and safety metrics. Khosla Ventures: Khosla Ventures is a venture capital firm with investments in AI, biotech, and other emerging technologies. It is co-leading Arena's Series B alongside Lightspeed, backing the development of benchmarks for AI alignment. The participation underscores commitment to trusted, data-driven AI assessment tools. M. Angelopoulos: M. Angelopoulos serves as CEO of Arena, leading the company's efforts in AI safety and evaluation. Angelopoulos is featured in the announcement highlighting the Alignment Index and the company's growth trajectory. The leadership is directing expansion into additional safety signals and modalities. Endeavor Catalyst: Endeavor Catalyst invests in high-growth technology companies, often with a focus on scalable AI and software solutions. It took part in Arena's Series B, supporting the launch of the Alignment Index and platform expansion. The investment helps advance neutral, real-world AI safety benchmarks. Salesforce Ventures: Salesforce Ventures invests in cloud, enterprise, and AI-focused startups. It participated in Arena's Series B to support advancements in AI agent evaluation and safety. The involvement aligns with broader enterprise interest in reliable AI tools for real-world applications. Dell Technologies Capital: Dell Technologies Capital focuses on investments in enterprise technology, infrastructure, and AI innovations. It participated in the Series B for Arena, aiding growth in AI evaluation infrastructure. The backing reflects interest in tools that enhance safe deployment of AI agents. Lightspeed Venture Partners: Lightspeed Venture Partners is a venture capital firm investing in technology companies across sectors including AI and enterprise software. It is co-leading Arena's Series B round, signaling support for independent AI evaluation platforms. The firm is contributing to scaling Arena's mission in real-world AI safety measurement. Benchmark Launch: Arena has introduced the Alignment Index as a new benchmark derived from real-world agent interactions to assess safety signals including unauthorized actions and deceptive behaviors. Investor Support: A group of established venture firms led the funding round, affirming confidence in independent, data-driven approaches to evaluating AI alignment beyond traditional static tests. Platform Expansion: Arena is extending its evaluation capabilities to additional safety signals, modalities, and agentic features to address growing autonomy in AI systems.