Mach Industries, a defense technology startup founded by 22-year-old Ethan Thornton, has raised $300 million in a new funding round that pushes its valuation to $1.8 billion — a fourfold increase from last year.

The company already has five autonomous vehicles in development and recently completed a major acquisition, according to TechCrunch. This rapid expansion underscores the surging investor appetite for next-generation defense technology.

Thornton's startup is part of a wave of young defense firms attracting significant capital as governments modernize military capabilities. The fresh funding will likely accelerate Mach's development pipeline and fuel further growth.

While the valuation jump reflects strong market confidence, critics question whether early-stage defense startups can maintain this momentum amid regulatory hurdles and long procurement cycles.

Some industry observers also caution that high valuations in this space may not account for the risks of government contract delays or shifting geopolitical priorities.