Castelion Stock for Accredited Investors

Defense Technology
By UpMarket Research  |  Last updated: September 2026
CEO Bryon Hargis Founded 2022 HQ El Segundo, US

Castelion is a private defense technology company founded in 2022. It designs and manufactures low-cost, mass-producible hypersonic strike systems and other next-generation military hardware for national security customers. In August 2026, Castelion raised $1 billion in its Series C at a $13 billion post-money valuation, led by JPMorganChase Strategic Investment Group, Andreessen Horowitz and Carlyle (TechCrunch and Axios).

Access to pre-IPO shares is available to accredited investors through UpMarket.

Last Reported Valuation
$13B
Series C, 08/19/26, TechCrunch and Axios
UpMarket Estimate
$15.3B
Based on UpMarket valuation model

How to Invest in Castelion Through UpMarket

Castelion shares are not on public exchanges. UpMarket provides accredited investors access through secondary market transactions.

Step 01

Verify accredited investor status

Confirm eligibility under SEC Rule 501 of Regulation D. Income or net worth threshold applies.

Step 02

Create an UpMarket account

Complete KYC/AML onboarding. Typically 1–2 business days. Licensed rep assigned on signup.

Step 03

Review available Castelion offerings

Full offering memoranda and risk disclosures provided before any commitment is required.

Step 04

Complete subscription documents

Review and sign subscription agreement. All documents handled digitally through the platform.

Step 05

Fund your investment

Wire transfer or ACH. $50K minimum. Funds held in custodial account until close.

Pre-IPO investments are illiquid, speculative, and involve risk of total loss of capital.

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Valuation Growth Over Time

Post-money valuation by round
Previous rounds Most recent
DateRoundAmount raisedValuation
Aug 2026 Series C $13B

Castelion's most recent reported round is its Series C, announced August 19, 2026. The round, led by JPMorganChase Strategic Investment Group, Andreessen Horowitz and Carlyle, valued the company at a reported $13 billion. Source: TechCrunch and Axios. Data as of September 26, 2026.

Castelion Revenue and Growth

Annual revenue

Why Investors Are Watching Castelion

Growth Signal

Castelion raised $350M to scale hypersonic production

Castelion said it closed a $350 million Series B to mass produce hypersonic munitions, directly targeting a top Pentagon modernization priority. The company previously raised a $100 million round in January 2025, showing rapid capital accumulation.

Market Opportunity

Pentagon demand centers on affordable hypersonic munitions

Castelion says the U.S. needs an affordable, mass-produced long-range hypersonic deterrent, framing a large defense procurement opportunity. TechCrunch reported the company is building a hypersonic missile business around high-volume production for this market.

Team & Talent

Former SpaceX engineers are building Castelion's defense stack

Forge Global describes Castelion as a defense technology startup led by former SpaceX engineers. TechCrunch also reported Lightspeed and Altimeter led the $350 million round, signaling strong investor backing for the team.

Interested in Castelion stock? Fill out the form above or sign up directly. Subject to availability. Accredited investors only.

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Castelion Stock FAQ

No. As of August 2026, Castelion is a private company and does not trade on any public stock exchange. Accredited investors can access Castelion shares through UpMarket, a FINRA-registered broker-dealer that specializes in pre-IPO investments.

Castelion does not have a public stock price because it is privately held. The most recent known share price comes from its last funding round. Pre-IPO share prices on the secondary market may differ from the last round price depending on supply, demand, and market conditions.

Yes. Accredited investors can indicate interest in Castelion shares through UpMarket by filling out the form on this page or creating an account at upmarket.co. All pre-IPO offerings are subject to availability and require a $50,000 minimum investment. UpMarket is a FINRA-registered broker-dealer and has brokered alternative investments since 2019.

Pre-IPO investments carry significant risks. Castelion shares are illiquid, meaning there is no public market to sell them quickly. There is no guaranteed exit timeline or return. The investment is speculative in nature, and investors should be prepared for the possibility of total loss. Valuations of private companies can fluctuate substantially between funding rounds. Investors should consult their financial advisor and review all offering documents before investing.

In a pre-IPO transaction, accredited investors purchase shares from existing shareholders (such as employees, early investors, or other holders) through secondary market platforms. The company itself does not issue new shares in these transactions. UpMarket facilitates these trades as a FINRA-registered broker-dealer, handling compliance, documentation, and settlement on behalf of both parties.

There are two primary exit paths for pre-IPO holdings: selling your shares on the secondary market to another buyer, or holding until the company completes an IPO or is acquired. Both paths are subject to transfer restrictions, company approval (right of first refusal), and market conditions. The timing of any exit is unpredictable, and investors should plan for a multi-year holding period.

The minimum investment for most pre-IPO offerings on UpMarket is $50,000. This amount may vary depending on the specific offering and share availability. There are no fees to create an UpMarket account or browse available investments. Investors only pay transaction-related fees when they complete an investment.

UpMarket's valuation estimate is derived from a proprietary model that incorporates multiple data sources: funding round data (Caplight), revenue estimates (Sacra), secondary market pricing, and public company comparables. The model applies a private company discount to the public comp multiple to account for illiquidity and information asymmetry. This estimate is not investment advice and may differ substantially from the price at which shares actually trade.

Castelion was valued at $13B in its August 2026 Series C. Accredited investors can request Castelion access through UpMarket.

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