Flourish raises $500M to build an AI system modeled on the human brain

The round values the New York startup at $2.5 billion. Jeff Bezos committed close to $100 million personally, nearly doubling an initial $50 million pledge. Lux Capital, GV and Catalio Capital filled out the rest. Funding talks began in late April 2026, and the round closed in about five weeks. Founders are former Amazon executive Rob Williams and neuroscientist Thomas Reardon. The company has no commercial product yet. Its system, called Cortex AI, targets a power budget of 20 to 50 watts. The money is meant to fund research that could take five to ten years to fully realize. The raise landed in a record quarter. North American startup investment totaled $137.2 billion in Q2, and giant rounds, not higher deal counts, drove the high totals. Flourish is a bet on a different architecture from scaled transformers, and it faces architecture-layer rivals including Groq, Cerebras and Etched. Those rivals focus on hardware efficiency, while Flourish is pursuing a biological route. For founders, the round shows that investors will still fund a pre-product, long-horizon research thesis when it targets AI's energy and compute costs. It also shows how concentrated capital has become: a few well-connected backers can close a half-billion-dollar round in weeks. Teams building on current LLM stacks should treat the efficiency-first pitch as a possible long-term competitive threat, though a commercial timeline is not yet public.