AI startup Flapping Airplanes raises $1B Series A at $6B valuation

Flapping Airplanes, a one-year-old AI startup focused on reducing data requirements for large model training, announced on October 21, 2026 that it has raised a $1 billion Series A round co-led by Index and Lux, at a valuation of $6 billion.

The funding comes just nine months after the company launched with a $180 million seed round from GV, Sequoia, and Index, which valued the startup at $1.5 billion. Existing backers including Sequoia, GV, and Kleiner Perkins also participated in the Series A, with Valor, Atreides, Kleiner Perkins, A*, and Nvidia among the company's investors.

Founded by Aidan Smith and brothers Asher and Ben Spector, Flapping Airplanes is developing a megakernel framework that aims to run training and inference workloads more efficiently on GPUs, with the goal of building intelligent systems that require less data and lower training costs. The company said the new capital will be used for hiring and advancing its research goals.