Mach Industries, a defense technology startup, announced it has secured $600 million in a Series C extension round, doubling its valuation to $3.7 billion. This follows an initial Series C round in June that raised $300 million at a $1.8 billion valuation. Investors participating in both rounds include Ribbit Capital, Infinite Capital, Bedrock Capital, and Sequoia.

The company has shown rapid growth, with its valuation rising from $470 million in a $100 million round earlier in 2023 to its current multi-billion dollar status. Mach Industries develops a range of unmanned military vehicles and weapons systems, including vertical takeoff and landing drones, long-range strike systems, and counter-drone technologies. Its main manufacturing facility spans 115,000 square feet in Huntington Beach, California, with additional sites across the state.

Mach positions itself as a builder of highly integrated defense systems that are more cost-effective than those from traditional contractors. In May, it acquired solid rocket motor startup Exquadrum for $50 million in cash and equity, outbidding several competitors. This acquisition addresses a shortage of solid rocket motors in the drone market, which has been dominated by two major suppliers.

The Exquadrum acquisition has led to the creation of Mach Energetics, a new division focused on producing solid rocket motors, jet engines, and energetic systems for external customers. Founded by 22-year-old Ethan Thornton, who left MIT at 19 to start the company, Mach Industries exemplifies the growing interest of Silicon Valley venture capital in defense technology. Notably, Sequoia Capital made its first defense tech investment with Mach.

Earlier this year, Mach secured a contract with the U.S. Army, further validating its technology and business model. Ribbit Capital, originally known for fintech investments, has also become a prominent backer, expanding its portfolio into defense and AI-related startups.