Castellum: The Defense Roll-Up That Does Its Buying in ...

This is one profile in a set on cleared government contractors and the different ways the people who build them turn engineering work into real wealth. The rest of the set mostly features private buyers, private equity funds that assemble small firms into bigger ones behind closed doors, a pattern laid out in Built to Be Bought. Castellum runs the exact same buy-and-build play. It just runs it in public, on a stock exchange, paying for its acquisitions largely with its own shares. That one difference changes everything about how the machine looks from the outside, because every move it makes is filed, priced, and recorded in real time.

From a pet company to a defense roll-up

Castellum's origin is a genuine curiosity, and it says a lot about how these public shells work. The company that is now a Navy-focused defense contractor was incorporated in Nevada in 2010 under the name Passionate Pet, Inc., then became Firstin Wireless Technology in 2013 and BioNovelus in 2015, according to its own registration statement filed with the Securities and Exchange Commission. The defense business arrived through the back door. In June 2019 the shell acquired a company called Bayberry Acquisition Corporation, controlled by Jay Wright and Mark Fuller, in a reverse merger, and in January 2020, after buying an electronic-warfare training firm called Corvus Consulting, the whole thing was renamed Castellum, Inc.

For its first years Castellum traded over the counter, in penny-stock territory. Then in October 2022 it did a 1-for-20 reverse stock split and uplisted to the NYSE American exchange under the ticker CTM, pricing a 3 million dollar public offering at 2 dollars a share. That uplisting is the important part. It gave Castellum a publicly traded currency, its own listed stock, to go shopping with.

Seven companies, mostly bought with stock

Since 2019 Castellum has completed seven acquisitions, and the striking thing is how it paid for them. This is a roll-up assembled substantially in its own shares rather than in cash or bank debt.

It bought Corvus Consulting in 2019 for about 9.6 million dollars, then folded in a string of small federal-services firms: MainNerve Federal Services in early 2021, in an all-stock deal; Merrison Technologies in August 2021, paid mostly in shares; Specialty Systems, Inc., days later, this one with a bank term loan and a seller note; a Pax River engineering business in November 2021; Lexington Solutions Group in 2022; and, in March 2023, Global Technology and Management Resources, a roughly 6.6 million dollar deal in which more than 80 percent of the price was paid in restricted Castellum stock, structured as a tax-free reorganization.

That last detail is the whole model in miniature. When a private equity fund buys a tuck-in, it pays with fund money and leverage, and the seller usually rolls a slice of equity in the new private platform. When Castellum buys one, it can simply print new shares and hand them over, and the seller becomes a public shareholder. It is the identical buy-and-build logic, run with a different, and much more visible, kind of money.

The currency is dilution

Paying in stock is not free, and the cost has a name: dilution. Every share Castellum issues, whether to buy a company or to raise cash, divides the ownership of the whole a little more thinly. The company's own filings show how fast that adds up. Its share count climbed from about 53 million shares in March 2024 to about 94.6 million shares by March 2026, according to the cover pages of its annual reports, an increase of roughly 78 percent in two years. Some of that came from acquisitions and some from a steady series of stock sales to fund the business, including a December 2024 offering priced at just 38 cents a share.

This is the trade-off that defines Castellum, and it cuts both ways. A private roll-up funds the same string of one to ten million dollar tuck-ins with fund equity and bank leverage, and none of it is visible to outsiders until an eventual sale. Castellum, because it is public and capital-hungry, has to file a disclosure and price an offering in the open market nearly every time it needs money, turning its dilution into a matter of continuous public record. The upside of that path is transparency and very little debt. The cost is that existing shareholders watch their slice shrink in real time.

What it does, and the turn toward profit

Underneath the financial machinery is a real contractor. Castellum does cybersecurity, software and systems engineering, information and electronic warfare, and program support, almost entirely for the federal government and heavily for the Navy. Its top three contracts made up more than half of its revenue in 2025, with customers including Naval Air Systems Command and Naval Sea Systems Command. In February 2025 its GTMR subsidiary won a prime contract worth up to 103.3 million dollars supporting a Navy special-missions program, and in 2026 a Castellum joint venture won a seat on a 250 million dollar Navy logistics IT vehicle, one of dozens of companies eligible to compete for the task orders that flow through it.

And the numbers have turned. Castellum's revenue grew to about 52.4 million dollars in 2025 from about 44.6 million in 2024, and it narrowed its net loss to roughly 2.5 million dollars from about 10 million the year before, reporting in November 2025 its first quarter of positive net income under standard accounting while paying down its debt. For a company that spent years bleeding cash, that is a real inflection, even if a single profitable quarter is not yet a track record.

The honest note

This series does not airbrush, and Castellum's risks are worth stating plainly, mostly because the company states them plainly itself. Its annual report warns directly that future financing "may involve substantial dilution" to existing shareholders, which is not a hidden danger but a disclosed feature of how the business is built. It reported net losses every year through 2024, with the largest, in 2022 and 2023, running into the tens of millions and including a non-cash writedown when its own stock price fell. It carried out a 1-for-20 reverse split and has priced stock sales below a dollar a share. And more than half its revenue rides on its three biggest contracts, the normal concentration risk of a small government contractor. None of that is wrongdoing. It is the ordinary, and unusually visible, arithmetic of trying to build something real on a micro-cap balance sheet.

The ledger reading

Strip away the ticker and Castellum is the same machine as the rest of this series, with the walls made of glass. A buyer assembles small, cleared, hard-to-replicate firms into something larger and more valuable than the sum of the parts. The only real difference is where the money comes from and who gets to watch. A private sponsor does this with a fund and leverage, and the compounding accrues to the fund and a narrow group of managers, unseen until the exit. Castellum does it with public stock, so the ownership of the compounding is spread across anyone who buys a share, and every dilutive step is disclosed the day it happens.

That visibility is the lesson worth keeping. The idea underneath The W-2 Trap is that wealth comes from owning the asset that compounds rather than drawing a wage from it, and a roll-up is a bet on making the whole worth more than the pieces. Castellum lets you watch that bet get placed, financed, and marked to market in real time. Whether it pays off for the shareholders diluted along the way is a question the public filings will answer in public, which is more than the private version of this machine ever offers.

Fact-check notes and sources

Corporate lineage (incorporated in Nevada in 2010 as Passionate Pet, later Firstin Wireless and BioNovelus), the 2019 reverse merger with Bayberry Acquisition Corporation controlled by Jay Wright and Mark Fuller, and the January 2020 renaming to Castellum after the Corvus Consulting acquisition: the company's SEC registration filings and the name-change announcement.
The October 2022 1-for-20 reverse split and NYSE American uplisting under CTM with a 3 million dollar offering at 2 dollars a share: Castellum. Glen Ives became chief executive on July 1, 2024, succeeding co-founder Mark Fuller: Castellum.
Seven acquisitions since 2019, several paid substantially in stock, including MainNerve (all-stock, 2021), Merrison (2021), Specialty Systems (2021), a Pax River business (2021), Lexington Solutions Group (2022), and GTMR (2023, more than 80 percent in restricted stock): the deal announcements for MainNerve, Merrison, Specialty Systems, Pax River, Lexington Solutions Group, and GTMR.
Share count rising from about 53 million (March 2024) to about 94.6 million (March 2026), roughly 78 percent, and a December 2024 offering priced at 38 cents a share: the cover pages of Castellum's annual reports on Form 10-K and the December 2024 offering.
GTMR's up-to-103.3 million dollar Navy prime contract (February 2025) and a joint-venture seat on a 250 million dollar Navy IDIQ (2026): Castellum on GTMR and Castellum on the IDIQ. IDIQ figures are ceilings, not guaranteed revenue.
Revenue of about 52.4 million dollars in 2025 (up from about 44.6 million in 2024), a net loss narrowed to roughly 2.5 million from about 10 million, and a first quarter of positive net income reported in November 2025: Castellum's third-quarter 2025 results and investor releases. Prior-year loss figures for 2022 and 2023 are drawn from the company's financial reports and are described here in approximate terms. The dilution risk language is disclosed in Castellum's own annual report risk factors.

This post is informational and journalistic, describing a publicly reported company, its people, and public filings. It is not investment, tax, legal, or M&A advice, and nothing here is a recommendation to buy or sell any security. All parties are discussed from public records and their own published statements as nominative fair use, with no affiliation implied and nothing endorsed by them.

Castellum: The Defense Roll-Up That Does Its Buying in Public