RL Province 69% tokens, cost structure directly restructured

Exa, an AI search engine founded by Harvard alumni, completed a $250 million Series C funding round led by a16z, with a post-money valuation of $2.2 billion. The funds are used to expand self-built indexes, train a new generation of retrieval models, with throughput reaching tens of thousands to hundreds of thousands per second. The core moat is a full-stack self-build: independent crawlers, native indexes tracking over 5 trillion URLs, self-developed embeddings, and the third-generation vector database, replacing "wrapped Google." Monthly query volume is 1 billion, and RL training can save 69% of tokens. Clients include leading AI companies like Cursor and Cognition.