How a Gen Zer built a $3.7 billion defense tech startup backed by Sequoia

Hi, it’s Preston Fore, in for Allie. Earlier this month, defense tech firm Mach Industries raised $600 million in a Series C extension at a $3.7 billion valuation.

That’s more than double the $1.8 billion valuation Mach reached just three months earlier when it raised its initial $300 million Series C led by Ribbit Capital, Infinite Capital, Bedrock Capital, and Sequoia Capital. But perhaps more striking than the pace of the raises is who’s leading them: Mach, which builds autonomous defense systems, is run by a 22-year-old.

Founder and CEO Ethan Thornton launched Mach in 2023 at 19, after developing an interest in defense as a teenager. Since then, he’s built the company around a willingness to move quickly, take risks, and adapt as its technology and the broader defense industry evolve.

“You’re never going to know everything, especially when you’re starting young, and you shouldn’t expect to,” Thornton told Fortune. “If you wait until you have all the answers, you’ll probably never start.”

By 2024, Mach landed a deal with the Army Applications Laboratory to develop a vertical-takeoff precision cruise missile—and the company’s momentum has only accelerated since.

Today, the Gen Zer is running a company with six weapons programs, a 115,000-square-foot headquarters and manufacturing facility in Huntington Beach, California, and ambitions to build everything from airframes and jet engines to solid rocket motors, energetic systems, and autonomous technologies.

The company’s rapid growth comes amid a broader boom in defense tech. Allie reported earlier this year that a record $19.8 billion was deployed into the sector in the first quarter of 2026 alone. Thornton, however, is betting that Mach can do more than simply ride that wave. After several years spent........

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