# Castellum

Castellum is an Asset Manager based in Vienna, United States.

## Overview

- **Organization type:** Asset Manager
- **Headquarters:** Vienna, United States
- **Region:** North America
- **Address:** Vienna, VA, United States
- **Founded:** 2019
- **Assets under management:** Undisclosed
- **Website:** castelluminc.com

## Regulatory record

- **CRD number:** 315891
- **Registration status:** Registered
- **Reports private funds:** No
- **IAPD record:** https://adviserinfo.sec.gov/firm/summary/315891

## About

Castellum, Inc. is a state-registered investment adviser with approximately $3 million in regulatory assets under management. The firm has 1 employee and 1 investment adviser. It operates with a small team.

## Sectors

- Cybersecurity
- Enterprise Software
- Defense & Government Services

## People

- Mark C. Fuller — Chairman and Chief Executive Officer
- Glen R. Ives — President and Chief Operating Officer

## Questions

### What is Castellum's acquisition strategy?

Castellum targets small to midsized U.S. federal government contractors with active contract vehicles, security clearances, and prime contractor status — particularly in cybersecurity, information warfare, and software engineering. The firm looks for companies generating $2–$10 million in annual revenue that lack the scale to pursue larger procurement opportunities independently. Once acquired, these subsidiaries are integrated into a platform that can bid for higher-value task orders from agencies like the Department of Defense and the U.S. Navy.

### Who runs the day-to-day operations at Castellum?

Chairman and CEO Mark Fuller leads strategic direction and acquisition sourcing, while President and COO Glen Ives runs operational integration and government customer relationships. Ives joined in 2021 after a career that included commanding officer roles in the U.S. Navy. The senior team is intentionally staffed with former military officers, which Castellum's filings describe as a competitive advantage when navigating the Department of Defense's procurement culture.

### What sectors does Castellum actively avoid?

Castellum focuses narrowly on federal IT, cybersecurity, and defense-related technology services — it does not pursue commercial enterprise IT, consumer software, state and local government contracts, or international government work. The company's filings describe its addressable market as U.S. federal agencies with national security missions, primarily the Department of Defense.

### What are Castellum's subsidiary companies?

Known subsidiaries from public announcements and SEC filings include Mainnerve Federal Services (cybersecurity services), Merrison Technologies (IT and cloud services for defense clients), Corvus Consulting (systems engineering and program management), and Lexington Solutions (software development and data analytics). These were all acquired between 2020 and 2021. Castellum has signaled it intends to add further operating units through its 2024 shelf registration.

## Related profiles

- [Fold Holdings](https://altss.com/profile/fold-holdings-inc)

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Last updated: 2026-06-03T20:00:00.000Z

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