Mach Industries, the three-year-old defense tech startup run by 22-year-old founder and CEO Ethan Thornton, has raised a $300 million Series C at a $1.8 billion valuation, the company announced on Monday.

The raise nearly quadruples the valuation of the company in a year. In June 2025, Mach raised $100 million at a $470 million valuation. Other investors include Bedrock Capital, Sequoia Capital, and Khosla Ventures.

The round was led by deep tech fund Infinite Capital and Ribbit Capital, known for fintech and lately in hot deals everywhere — from AI coding startups like Cognition to neoclouds like Crusoe.

Since building autonomous weapons is a capital-intensive industry, Thornton began actively fundraising a couple of months ago, he told TechCrunch, and quickly discovered that the round would be popular with investors.

“We went out to raise 200 [million dollars] and we were extremely oversubscribed at 200 and happy with the price, so we decided to push up to 300. We’re still oversubscribed at the 300 mark,” Thornton said of the fundraising efforts.

Founded in 2023, Mach and its growth have been a wild ride for Thornton, who famously dropped out of MIT at 19 to start the company. VC enthusiasm is high for a few reasons. Other than AI, defense tech is a hot area for investment right now as newfangled autonomous weapons and drone defense systems prove themselves in battle in Ukraine.

Mach has also become prolific in its short time. The Huntington Beach, California-based company now has five autonomous vehicles in development: Viper, a jet-powered vertical takeoff vehicle; Glide, a high-altitude glider capable of launching weapons; Stratos, an airborne surveillance platform; Dart, a low-cost counter-drone interceptor; and Pike, intended for launching long-range munitions. Production is expected to begin next year on at least three of these systems, the company says.

Plus, just this week, it won a Department of Defense contract to create a new, sixth vehicle that the startup has never discussed publicly, Thornton tells TechCrunch. The contract is from the Defense Innovation Unit (DIU) to develop the Navy’s new “runway-independent strike aircraft,” as the startup describes it.

This will be for a very large aircraft, Thornton says, that could have applications in the commercial industry, too.

It has also grown from about a dozen employees in its first year to about 350 employees today, has a 115,000-square-foot manufacturing facility in Huntington Beach, and design and production facilities in a number of other locations.

“So by the end of this year, in 2026, we will have brought on four new production facilities,” Thornton said.

But another reason VCs wrote big checks is that last month, Mach orchestrated an industry coup (excuse the pun) when it acquired solid rocket motor (SRM) startup Exquadrum in a $50 million cash-and-equity deal, as TechCrunch previously reported. It beat out upward of eight other potential buyers, the startup said.

There’s an acute shortage of SRMs as drones create unprecedented demand in a market controlled by two of the major prime defense contractors, Aerojet Rocketdyne and Northrop Grumman. The lead times for purchasing can stretch years.

With this buy, Mach controls its own destiny for rocket motors and also launched a new commercial business, Mach Energetics, to sell the engines. While Thornton declined to share revenue, he said the current mix is 50/50 between selling to the government and selling to other companies.

Thornton remembers a moment last year when all the fast growth of the company really hit him. Two years ago, the all-hands meetings were held in the conference room with “like 12 people,” he said. “At our two-year party we had like 200 plus chairs and it was standing-room only.”

Still, he said, he’s most proud of the speed of product development. That is, after all, the entire reason for his company and for the defense tech industry. The idea with these startups, backed by tech VCs, is to bring faster, more affordable products to the military and related commercial uses, as opposed to the expensive, bespoke offerings that legacy prime defense contractors offer.

“Traditionally, it’s four years to build a jet engine. That’s about the fastest you can find in this space. And we went from no team to building a team to a jet engine firing in about eight months,” Thornton said.