Flapping Airplanes, a San Francisco AI research lab founded in late 2025, has raised $1B at a $6B valuation, led by Index Ventures and Lux Capital, Bloomberg reported. Its valuation has quadrupled since January. It is working on ways to train AI with less data and compute, and has no product yet.

Flapping Airplanes, an AI research startup founded in late 2025, has raised $1B at a $6B valuation, Bloomberg reported on Wednesday. Index Ventures, which raised $2B in August to back more AI firms, led the round with Lux Capital. Sequoia Capital, Alphabet’s GV and Kleiner Perkins also took part.

The San Francisco company’s valuation has quadrupled since January, when it raised a $180M seed round. It has no product on sale yet.

Flapping Airplanes is one of a growing group of AI “ neolabs ”, startups that focus on research before building products.…