AI Startup Flapping Airplanes Is In Talks To Raise Funding At A $5 Billion Valuation

AI startup Flapping Airplanes is in talks to raise capital at a $5 billion valuation, multiple sources familiar with the deal told Forbes. VC firms Index Ventures and Lux Capital are leading the round and Kleiner Perkins is participating, the sources said. The raise is in the hundreds of millions, they added. The San Francisco-based startup was cofounded in 2025 by brothers Ben Spector, 25, and Asher Spector, 26, and Aidan Smith. In January, it raised a $180 million seed round that included Sequoia Partner David Cahn. The company is developing AI training methods that require less data, according to its website. Flapping Airplanes is among a growing group of so-called neolabs that raise large sums to do frontier research instead of building products or making revenue in the near term. Others like Ineffable Intelligence, founded by Google DeepMind researcher David Silver, are trying to solve similar data-related problems. The London-based company raised $1.1 billion to train AI that does not need human data at all. Flapping Airplanes did not respond to Forbes' request to comment. Index Ventures, Lux Capital and Kleiner Perkins declined to comment.