AI Startup Flapping Airplanes Raises $1B Series A at $6B Valuation

Flapping Airplanes, a year-old AI startup developing ways to train large models with less data, said Wednesday it raised a $1 billion Series A round co-led by Index and Lux at a reported $6 billion valuation. The valuation quadrupled from the $1.5 billion set during its $180 million seed round nine months earlier. The round drew returning backers Sequoia, GV and Kleiner Perkins, along with Valor, Atreides, A* and Nvidia. The company was founded by Aidan Smith, a former Thiel fellow who worked at Neuralink, and brothers Asher and Ben Spector, both Stanford PhD candidates. Flapping Airplanes is building a "megakernel" framework that bundles GPU tasks into a single program, claiming it can overlap memory-bound inference with compute-bound training so chips rarely sit idle. The founders argue AI has barely tapped GPU capacity and aim to build systems that cost far less to train and run.