Arena 完成 2 亿美元 B 轮融资，估值达 31 亿美元
LMArena 母公司 Arena 融了 2 亿美元，估值 31 亿，还推出了测智能体是否可信的 Alignment Index，评测圈大事件。
Arena 宣布完成 2 亿美元 B 轮融资，估值 31 亿美元，由早期投资方 Felicis 持续支持。公司年化收入已超过 1 亿美元，累计促成 3.5 亿场评测会话和 6200 万次用户投票。随融资一同发布的 Alignment Index 用于衡量 AI 智能体是否安全、真实地按用户指令行事。Arena 的评测结果来自真实用户互动，定位为行业可信度测量层。
We’re so proud to have worked alongside @felicis from the very beginning! Peter Deng @pxd When @Felicis first invested in @Arena at the seed, we believed the company was building something essential: an independent, community-driven source of truth for measuring the AI frontier. That conviction only grew, and we went on to lead the Series A. The progress since then has been extraordinary. Arena has surpassed $100 million in annualized revenue, facilitated 350 million sessions and 62 million votes, and grown into one of the world’s largest AI communities. Today, Arena announced a $200 million Series B at a $3.1 billion valuation, alongside a new Alignment Index that measures whether AI agents behave safely, truthfully, and within the bounds of what users actually ask them to do. As AI systems begin taking real actions on our behalf, measuring capability is no longer enough. We also need to know whether these systems can be trusted. Arena is uniquely positioned to give the industry that answer, grounded in millions of real-world human interactions. We are true believers in @ml_angelopoulos , @infwinston , and the entire Arena team as they build the trusted measurement layer for AI. arena.ai/blog/series-b 🔗 View Quoted Tweet 💬 1 🔄 0 ❤️ 4 👀 1994 📊 1 ⚡