Flapping Airplanes Raises a $1 Billion Series A Co-Led by Index and Lux, Reportedly at a $6 Billion Valuation

A lab of a couple dozen people, by Index's count, has raised $1 billion on what Index describes as the founders' belief that AI could be orders of magnitude more efficient. Flapping Airplanes announced on Wednesday, October 21 that it had raised a $1 billion Series A co-led by Index Ventures and Lux Capital, TechCrunch reports, "reportedly at a $6 billion valuation." TechCrunch says the round comes nine months after a $180 million seed from GV, Sequoia and Index that valued the company at $1.5 billion, so its valuation "just quadrupled," by TechCrunch's arithmetic.

The bet

The San Francisco lab was founded by Aidan Smith and brothers Asher and Ben Spector, according to TechCrunch. The founders describe their work as "the world's most complete megakernel framework," which they say can run training and inference in a single GPU kernel, with the goal of building intelligent systems "without ingesting half the internet." Index, which says it led the seed and is leading the Series A, says the team is "a couple dozen people," all working in person, and that partner Mark Xu joins the board. Index argues that "demand for AI will continue to far outpace the supply of the key inputs, compute and data."

TechCrunch says earlier backers Sequoia, GV and Kleiner Perkins participated, and lists Valor, Atreides, A* and Nvidia among the company's investors.

Limits

• The $6 billion valuation is reported by TechCrunch and was not confirmed in the Index post we read.
• Neither TechCrunch nor Index describes a released product or published benchmarks, so the efficiency claims cannot yet be checked.

Sources

• TechCrunch: Year-old AI lab Flapping Airplanes raises $1B at a $6B valuation (October 21, 2026)
• Index Ventures: Toward More Efficient AI: Leading Flapping Airplanes' $1B Series A (October 21, 2026)