Private investment in defense tech gives America a strong advantage over our adversaries. Our investors believe in the future of the United States as much as Castelion does. Thank you to @nasdaq for featuring Castelion in Times Square!

.@hargsb joins CNBC's Morning Call today to talk about our $1 billion Series C round and why it’s critical that private capital is investing in U.S. defense systems in order to reindustrialize American manufacturing.

Castelion has earned trust and credibility by demonstrating technology that creates an asymmetric advantage and can be built at speed, cost, and scale. They’ve turned ambitious promises into flight-tested hardware and real production capacity for critical national security priorities. We believe they’re building one of the most important defense companies of this generation. Pumped to double down and proud to keep backing this exceptional team. 🇺🇸

Congratulations to @Castelion on its $1B Series C to rebuild America's advanced hypersonic weapons and other forms of deterrence. Castelion credits Blackbeard as the first American hypersonic missile engineered from inception to be mass-produced at low cost, and reports taking it from a clean sheet to a program of record in under four years. We're proud to double down on our partnership with @hargsb, Sean Pitt, Andrew Kreitz, and the entire team.

@Castelion is at the forefront of a generational shift in how the US tests, develops, and fields weapon systems at scale. @hargsb @sean_pitt_ & Andrew have done the hard stuff from the start. They have put our country in a safer position and changed how our military deters conflict. No one has moved this fast to develop a missile of this capability. In today’s world of evolving conflict, nothing is needed more than Castelion products. Congrats team.

Eight months after Erik Kriessmann (@ekriessmann) led @Castelion's Series B, Altimeter is pumped to deepen our commitment and continue our partnership with Bryon (@hargsb), Sean, Andrew, and the entire Castelion team as they announce their $1B Series C at a $13B valuation. Castelion is building with a rare combination of speed, technical ambition, and manufacturing scale. In just a few years, the team has taken Blackbeard from a clean-sheet design to flight-tested hardware and a program of record, secured more than $500M in U.S. military contracts, and has begun building what is currently the largest dedicated hypersonic missile manufacturing facility in the country. We believe Castelion is building one of the most important defense companies of this generation and demonstrating what is possible when American engineering and manufacturing move with urgency. Designed in California. Built in New Mexico. Supplied by businesses across America.

Deterrence depends on unapologetic American strength: weapon systems adversaries fear, produced in quantities they can't imagine, at a price taxpayers can afford.   Grateful to our Series C investors who are trusting us with the significant capital required to manufacture deterrence at scale and our customers for trusting us with their mission. Thank you for believing in us, we won’t let you down.

@Lightspeed first partnered with @hargsb, @sean_pitt_ and Andrew Kreitz in 2024. Today, we’re tripling down on Castelion as part of its $1B Series C. Building defense systems at scale requires moving quickly from test to production while keeping unit costs down. Castelion has built around both. Design, flight testing and manufacturing run as one continuous process, so what the team learns on the range can go directly into the next build. The first system Blackbeard, is already below $500K per unit, having gone from a clean-sheet design to a U.S. military program of record in 2.5 years. We’re excited to triple down on the Castelion team as they apply their years of experience scaling hardware production at SpaceX to additional strike and defensive systems. cc @ravi_lsvp, Prathik hosalli

Castelion is proud to announce our $1 billion Series C. We’re growing fast and our mission hasn't changed: build the weapons required to deter the next major war, affordably, rapidly, and at massive scale. This funding accelerates Blackbeard production, develops a longer-range strike system, and starts work on defensive systems. Thank you to @JPMorgan Chase's Strategic Investment Group, @a16z, @OneCarlyle, @lightspeedvp, @LavrockVC, @AltimeterCap, @TRowePrice, @generalcatalyst, and #Interlagos# for backing that work.

Whoever learns fastest wins over time. That happens through rapid prototyping, testing, and iteration. A responsive, capable machine shop makes that possible at Castelion. Here's how.

3, 2, 1, Castelion!  We hit a major milestone this month: more than doubling our workforce in the past year. We're recruiting excellent talent across all verticals. Join us. #AerospaceSummerGames2026#

Hypersonic missiles are a great deterrent, but they aren't built fast enough today. Rapid development schedules and affordable, mass-produced long-range strike are key to deterring future conflicts.