Taking Flight: Our Investment in Flapping Airplanes

Some entrepreneurs you meet, and it doesn’t matter what they’re building. You just know you want to be part of it. That has never been truer than when we met Ben and Asher Spector.

Mark has known Asher since they were students at Harvard, and separately built a close relationship with Ben through the Prod community, a student-run incubator co-founded and led by Ben. As their relationships developed over the years, he felt strongly that any company the brothers eventually decided to build would be one to partner with.

Not long after Mark joined Index, Shardul was catching up with Chris Ré when a tousled-haired student wearing glasses appeared in the professor’s office. It was Ben Spector. He and Shardul took an impromptu walk, connecting on values, decision-making, imagination, and irreverence. Ben struck Shardul as a generous, high-integrity, and exceptionally intellectual. Two hours later, when they finally parted ways, Shardul immediately called Mark and said, “Ben Spector is a sensation.”

As we spent more time with Ben and Asher, our conviction only grew. That feeling extended across the entire Index family – not just among our team, but among founders like Assaf, Olivier, Parag, and others who spent time with them at Index events. We heard words like “wow,” “impressed,” and “talented.” Later, when Asher mentioned to Mark on a walk that he and Ben were finally thinking of starting something, Mark texted Shardul: “In terms of feeling conviction… I can physically feel my excitement.”

Ben is one of those rare people who seems to raise the ambition of everyone around him. Through Prod, he played a meaningful role in the formation and early shaping of companies like Cursor, Mercor, Etched, Decart, and others. Founders and researchers describe him as someone who can quickly distill problems, reframe opportunities, and expand what feels possible. Even as they’ve built multi-billion-dollar businesses, Ben’s peers continue to call him for advice, while PhD students across Stanford, MIT, and Harvard – and researchers at leading labs and AI companies – increasingly seek him out for guidance.

Asher complements Ben with a more analytical, structured approach. He recently completed a PhD in Statistics at Stanford and has an uncanny ability to synthesize complex ideas and explain them clearly. A former North American debate champ, that background shows up in how he frames arguments, listens closely, and updates his thinking when presented with new evidence. Where Ben often pushes people to imagine what’s possible, Asher brings the structure and rigor to reason through how to get there. Together, they’re high-integrity people whose values and judgment make them natural magnets for exceptional talent. Their co-founder, Aidan Smith, is a Thiel fellow who worked at Neuralink for three years while still in college at Georgia Tech; he embodies the infectious energy and sincerity the team brings to everything they do.

Ben, Asher, and Aidan’s new foundational AI research lab, Flapping Airplanes, is built around a belief that today’s models could be orders of magnitude more data-efficient than they are now. Humans learn language and reasoning with a tiny fraction of the data modern systems consume, suggesting there may be entirely new learning paradigms still waiting to be discovered. Closing that gap will likely require new ways of thinking and the freedom to pursue radical, long-term ideas without being locked into a single technical path from day one.

For Ben, Asher, and Aidan, the name Flapping Airplanes is both a metaphor and a cultural signal. It reflects their willingness to question assumptions – to build a different kind of airplane – and to look for inspiration outside the usual playbook. That ethos extends to how they’re building the team: assembling what amounts to an Avengers-style lineup, hiring for specific superpowers, and pairing world-class researchers with exceptional young talent.

We’re thrilled to partner with Ben, Asher, Aidan, and their all-star team, and to co-lead this investment alongside our friends at GV and Sequoia. We have full belief in this team’s ability to build something truly transformative, and we couldn’t be more excited to be on this journey with them.