J2 Ventures announced the close of its $250 million oversubscribed Brookhaven Fund. The Boston-based venture capital firm focuses on technology that advances both commercial markets and U.S. national security. The fund secured commitments from JP Morgan, MetLife, Upsher Management, Alpha Leonis Partners, and the State Investment Council of New Mexico, along with additional institutional and family office investors. This marks one of the most significant early-stage funds dedicated to dual-use innovation.
The new fund builds on the firm’s strategy of investing at the intersection of government purpose and private sector scalability. J2 has positioned itself as a catalyst for founders working in areas where technological readiness, economic competitiveness, and national resilience align. The firm has consistently demonstrated strong outcomes through its approach of pairing early commercial potential with pathways to government adoption and public sector impact.
J2’s portfolio spans more than 35 companies through its prior funds, supporting innovation across health, infrastructure, and security. The firm’s team combines expertise in national security, science, entrepreneurship, finance, and policy, enabling it to assess opportunities across mission-critical and commercial dimensions. Its model also focuses on helping founders secure non-dilutive capital, with J2-backed companies historically raising $2 in non-dilutive funding for every $1 invested by the firm.
The Brookhaven Fund will invest in early-stage companies advancing technological capabilities in advanced computing, cybersecurity, communications infrastructure, artificial intelligence, and healthcare, particularly in remote physiological monitoring. J2 views these sectors as increasingly central to both national strategic priorities and scalable commercial adoption.
The firm has contributed to defining the modern dual-use category by integrating commercial growth disciplines with deep ties to defense and intelligence communities. Its portfolio includes companies such as Oura in wearable health technology, Aalyria in resilient global networking, Codemetal in AI translation for defense applications, Apex Space in satellite infrastructure, and Mesa Quantum in precision clock technology for next-generation communications.
The firm’s leadership team includes General Partners with backgrounds spanning the Air Force, Defense Innovation Unit, municipal technology leadership, the Small Business Administration, and special operations. J2 is also advised by senior leaders across the military, technology manufacturing, and academia, supporting founders navigating both market and operational complexity.
Brookhaven is J2 Ventures’ third consecutive oversubscribed fund, reflecting continued investor conviction in its performance and alignment with its mission. The firm states that its long-term goal is to accelerate the development of foundational technologies that strengthen national security while contributing to broader societal resilience and economic stability.
KEY QUOTES:
“There have been rocket-ship companies in every generation born out of early collaboration between national necessity and private ingenuity. Oracle began with a government project, Cisco and the early internet grew from federally funded research, and one of Pixar’s first customers came from the public sector. We’re entering a moment where urgency and investment are converging across both private venture and government to solve hard, consequential, and high-stakes problems. Brookhaven exists to accelerate that cycle, backing founders whose innovations strengthen not only national security but the everyday systems that keep society safer, healthier, and more connected.”
Alex Harstrick, Managing Partner and Co-Founder, J2 Ventures
“The most impactful innovation happens when founders are empowered with capital, insight, and access. Our goal with Brookhaven is to ensure that world-changing technologies don’t get stuck on the lab bench, that they reach scale, adoption, and global impact, all while preserving value for the founder.”
Jonathan Bronson, PhD, Managing Partner and Co-Founder, J2 Ventures
