Analysis
Castelion, the hypersonic-missile startup valued at $13 billion in its August Series C, has grown from 159 employees at the end of 2025 to more than 400 today as it races to turn that valuation into actual missile production, Fortune reported.
What does Castelion do?
Founded in 2022 by three former SpaceX executives -- chief executive Bryon Hargis, chief financial officer Andrew Kreitz and Sean Pitt -- Castelion is based in Torrance, California, and is building Blackbeard, a low-cost hypersonic missile that documents cited by Fortune say can be produced for under $500,000 each. The Pentagon has designated Blackbeard a "program of record," and the company is racing to open a roughly 1,000-acre production site in Rio Rancho, New Mexico, called Project Ranger. "Humans have done it, just not Americans," Hargis told Fortune of the broader hypersonic-missile challenge. "I firmly believe it's doable."
Castelion's funding history
Castelion's rounds, oldest first:
āGovernment contracts also take years to convert into recurring revenue, and a 1,000-acre New Mexico facility that isn't open yet is an execution risk, not a result.ā
- April 2023 seed ā $5.6M, led by Lavrock Ventures
- Seed extension ā $8.6M, led by Andreessen Horowitz
- Series A ā led by Lightspeed Venture Partners, amount undisclosed
- August 2026 Series C ā $1B total ($800M equity plus a $250M revolving credit line), $13B valuation, equity co-led by JPMorganChase's Strategic Investment Group, Andreessen Horowitz and funds managed by Carlyle; Lightspeed, Lavrock, Altimeter, General Catalyst, Interlagos and new investor T. Rowe Price Associates also participated, according to Pulse2
Who invested in Castelion?
Andreessen Horowitz led the seed extension and returned as an equity co-lead of the Series C alongside JPMorganChase's Strategic Investment Group and funds managed by Carlyle, while Lightspeed Venture Partners led the Series A and participated again in the $1 billion round, per Pulse2's reporting. T. Rowe Price Associates joined as a new investor in the Series C. Castelion has not announced a new priced round since August, so the $13 billion mark Fortune cites is the same figure set roughly two months ago -- the news here is execution against that price, not a fresh markup.
The caveat: Castelion's more than $500 million in disclosed government contracts, including a Navy award worth up to $200 million in September, is still a fraction of the $13 billion private-market valuation backing it.
Government contracts also take years to convert into recurring revenue, and a 1,000-acre New Mexico facility that isn't open yet is an execution risk, not a result. Whether Castelion can hit the production costs its own documents claim, at the volumes the Pentagon wants, remains the open question investors are underwriting.
Hypersonic missile market and competitors
Castelion's chief rival on hypersonics is Lockheed Martin's Dark Eagle program, which Fortune reports is running roughly three years behind schedule -- a gap Castelion is explicitly trying to exploit with a faster, cheaper design. Established primes RTX, Northrop Grumman, Boeing, BAE Systems and MBDA are also competing for the same government spending.
The global hypersonic-weapons market is projected to grow from $14 billion in 2026 to $25 billion by 2033, according to Coherent Market Insights.
Fortune's own comparison point is Anduril, the $61 billion defense-tech company that started with a narrower sentry-tower business before expanding into aircraft and munitions -- a reminder that today's valuation is a bet on where Castelion's product line goes next, not just where it is now.
What to watch next
The near-term test is whether Project Ranger opens on schedule and whether Blackbeard's unit economics hold up outside controlled test conditions. Pulse has tracked Castelion's rise through the two-speed defense-tech market before; its earlier look at Castelion and Shield AI found a similar pattern of young companies attracting prime-level valuations years before prime-level revenue.