J2 Ventures is a Boston based venture capital firm investing in technologies that strengthen both commercial markets and United States national security. The firm has built a reputation for backing dual use innovations that can scale in civilian markets while addressing critical defense and government needs. Its investment team brings deep experience from the Department of Defense, federal innovation units, health systems and advanced technical fields.
The Brookhaven Fund is J2 Ventures’ newly closed $250 million vehicle dedicated to accelerating early stage dual use technologies.
The fund is backed by a strong institutional LP base that includes JP Morgan, MetLife, Upsher Management, Alpha Leonis Partners and the State Investment Council of New Mexico, alongside additional institutions and family offices.
Brookhaven will focus on seed and Series A investments in companies building the next generation of critical infrastructure for computing, cyber defense, secure communications and AI enabled systems, as well as healthcare companies developing remote physiological monitoring capabilities with potential government deployment.
The fund expands upon J2’s track record across its first two funds, which backed more than 35 companies that collectively raised more than $1 billion in follow on capital and secured hundreds of millions in non dilutive government funding. The firm’s dual use approach positions Brookhaven as a specialized fund operating at the intersection of national security, deep tech and scalable commercial markets.
Leadership
The partnership is led by Managing Partners Alex Harstrick and Jonathan Bronson, PhD. The leadership team includes General Partner Dr. Matt Goldman, former Chief Medical Officer of the Defense Innovation Unit and retired Air Force Colonel, General Partner Christine Keung, former Chief Data Officer for the City of San Jose and former appointee at the Small Business Administration, and Master Chief (ret.) Adam Briley, a retired Navy SEAL who leads the firm’s federal programs practice.
Investment Strategy
J2 Ventures follows a dual use investment strategy rooted in identifying innovations that can serve both civilian and national security markets. The firm partners closely with founders who are building products that can benefit from government demand signals, federal funding pathways and commercial sectors simultaneously.
Its approach includes supporting startups through technical validation, regulatory navigation, federal contracting channels and long term commercialization planning. Brookhaven continues this model by concentrating capital on technologies that are strategically important to U.S. resilience and competitiveness.
Notable Investments
Across its prior funds, J2 Ventures has invested in more than 35 companies across health, infrastructure and security. Portfolio companies include:
Notable Exits
Public exits have not been disclosed.
Other
The firm has demonstrated strong ability to help companies access non dilutive government funding and align technologies with national security priorities.
Alexander Harstrick - Managing Partner, Co-Founder
Jonathan Bronson - Managing Partner, Co-Founder
United States
