J2 Ventures
J2 Ventures is a Boston-based early-stage venture capital firm investing in dual-use technologies across advanced computing, biomedical engineering, cybersecurity, and infrastructure for both commercial and U.S. national security markets.
- Company typePrivate
- Founded2021
- HeadquartersBoston, United States
- Headcount1–10
- GTM typeB2B
- OfferingServices
What J2 Ventures does
J2 Ventures is a Boston-based, early-stage venture capital firm founded in 2021 by Alexander Harstrick and Jonathan Bronson that invests in dual-use technologies with both commercial and U.S. national-security applications. The firm targets Seed and Series A rounds across four pillars: advanced computing, biomedical engineering, cybersecurity, and infrastructure. Its current and historical funds (~$52M in 2021, ~$69M in 2022, $150M in July 2024, and a $250M oversubscribed Brookhaven Fund in November 2025) have backed more than 30 portfolio companies, including Aalyria (space-based laser communications, $1.3B valuation), Code Metal (AI code translation, $1.25B valuation), Oura Ring, MesaQuantum, Phoenix Semiconductor, Principal Mineral, Aether Biomedical, Empress Therapeutics, Druid, Apex Space, and Parallel Fluidics.
The firm's revenue model is standard for an early-stage venture manager: management fees on committed or invested capital (typically around 2% annually on actively investing funds) plus carried interest on realized profits. Limited partners span institutional and family-office categories, including JP Morgan, MetLife, the State Investment Council of New Mexico, Upsher Management, and Alpha Leonis Partners. The team and advisor bench comprise PhD scientists, combat veterans, practicing physicians, and former Defense Innovation Unit, military, and federal-government leaders (including a retired Army Surgeon General and a retired Navy Vice Admiral), providing portfolio companies with strategic counsel and access to government/defense customers.
The core product offering is the Brookhaven Fund, a $250M oversubscribed vehicle dedicated to early-stage dual-use technology. The firm's value proposition centers on three pillars: government and defense network access, operational and scientific expertise, and capital efficiency through focused Seed/Series A investment. Geographic focus is the United States, with Boston as the operational headquarters and notable portfolio activity in supply-chain resilience (semiconductors, critical minerals, space-based communications) for U.S. national security.
J2 Ventures firmographics
Firmographics- Name
- J2 Ventures
- Legal name
- J2 Ventures
- Website
- https://j2vp.com
- Company type
- Private
- Founded year
- 2021
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- J2 Ventures is a Boston-based early-stage venture capital firm investing in dual-use technologies across advanced computing, biomedical engineering, cybersecurity, and infrastructure for both commercial and U.S. national security markets.
- Ownership category
- akta.pro rank
J2 Ventures industry classification
Industry- Product category
- Venture Capital / Private Equity
- NAICS
- Portfolio Management and Investment Advice (52394), Other Investment Pools and Funds (5259)
- SIC
- Investment Advice (6282)
- akta.pro primary industry
- Early-Stage Venture Capital (Series A/B) (FSANAAAB)
- akta.pro secondary industry
- Late-Stage Venture Capital (Series C+) (FSANAAAC)
Keywords
Where J2 Ventures is headquartered
LocationHeadquarters
- HQ city
- Boston
- HQ country
- United States
- HQ region
- North America
Markets served
J2 Ventures business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Operations, Marketing or Sales, Others
Revenue model
- Not disclosed: No revenue model information available in the provided source data.
Go-to-market motion1 record
J2 Ventures product offering
Product offeringCore offering
J2 Ventures is a venture capital firm that manages and deploys investment funds into early-stage dual-use technology companies serving both commercial markets and U.S. national security. Its flagship offering is the $250 million oversubscribed Brookhaven Fund, investing at Seed and Series A across advanced computing, biomedical engineering, cybersecurity, and infrastructure. Portfolio companies receive capital, strategic counsel, and direct access to government and defense networks through the firm's team of PhD scientists, combat veterans, practicing physicians, and former Defense Innovation Unit leadership.
Product overview
J2 Ventures is a venture capital firm — not a software product company — whose primary offering is the Brookhaven Fund, a $250 million oversubscribed investment vehicle dedicated to early-stage dual-use technology serving both commercial markets and U.S. national security, with prior funds including a $150 million dual-use fund closed in 2024. The firm invests primarily in Seed and Series A rounds across four focus areas: Advanced Computing (e.g., Aalyria for space-based laser communications, Code Metal for AI code translation, Femtosense for edge AI, Paravision for computer vision, VectorWave for edge computing, MesaQuantum for quantum sensing), Biomedical Engineering (e.g., Aether Biomedical, Empress Therapeutics, Lumia Health, Parallel Fluidics, Safi Biotherapeutics, Oura Ring, Tasso, Sealonix, Micron Biomedical, Somnair), Cybersecurity (e.g., Acalvio, Cinder, iCOUNTER, Kusari, Musubi, Nametag, Redcoat AI, Unit 221B), and Infrastructure (e.g., Aalyria, Apex Space, Arkenstone Defense, Druid, InfiniG, LightSource, Plato Systems, Principal Mineral, Ravn, SkyFi). The firm's value proposition centers on providing founders with strategic counsel, government and defense sector access, and operational expertise drawn from a team of PhD scientists, combat veterans, practicing physicians, and successful entrepreneurs.
Differentiator
Problem solved
Functional benefit
Brands
- Brookhaven Fund: J2 Ventures' third fund, a $250M oversubscribed fund dedicated to dual-use technology investing for U.S. national security and commercial markets.
Products and services
- Brookhaven Fund J2 Ventures' $250 million oversubscribed flagship venture capital fund dedicated to early-stage dual-use technology serving both commercial markets and U.S. national security. Targets Seed and Series A rounds across AI, cybersecurity, healthcare, and infrastructure.
- J2 Ventures Dual-Use Investment Fund Prior $150 million venture capital fund focused on dual-use technologies serving civilian and government applications, with emphasis on military healthcare, supporting founders across Seed and Series A rounds.
Companies that use J2 Ventures
Customer profileSegments1 record
Ideal customer profiles2 records
J2 Ventures technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
J2 Ventures partnerships and signals
Strategic signalRecent moves5 records
Expansion highlights5 records
J2 Ventures competitors and assessment
Company assessmentBroad incumbents
- In-Q-Tel: Strategic, not-for-profit investor for the U.S. intelligence community, deploying capital into dual-use startups. Comparable in national-security thesis but funded as a strategic vehicle rather than a traditional VC.
- Founders Fund: Peter Thiel's venture firm with a long-standing focus on defense, space, and government-tech investments (Anduril, Palantir). Comparable defense-tech orientation but operates at multi-billion-dollar fund scale.
- Andreessen Horowitz (a16z) — American Dynamism: Mega-fund's dedicated defense/manufacturing/infrastructure vertical investing in dual-use startups. Overlaps with J2's thesis at a much larger scale and broader mandate.
- Lux Capital: Larger, established venture firm investing in frontier science and tech, with a notable defense-tech allocation. Comparable in dual-use thesis but operates across broader sectors and at significantly larger fund sizes.
- B Capital: Global venture firm with a dedicated aerospace and defense practice. Comparable in dual-use tech orientation at later stages than J2's typical Seed/Series A sweet spot.
- General Catalyst: Large multi-stage venture firm with an active defense and government-tech practice (Heliogen, Vannevar Labs). Overlaps with J2 in dual-use Seed/Series A but is a generalist with a much larger fund.
- Khosla Ventures: Large venture firm with selective frontier-tech and dual-use exposure. Overlaps with J2 on technology themes (AI, bio, infrastructure) but as part of a much broader generalist portfolio.
Direct peers
- Shield Capital: Early-stage venture firm focused on dual-use commercial and national security technology. Most directly comparable peer to J2 — similar Seed/Series A stage, similar defense-tech thesis, and overlapping portfolio (co-invested in Code Metal).
- Overmatch Ventures: Venture firm investing in defense and dual-use technology startups at the early stages. Closely comparable to J2 in fund size, stage focus, and co-investment activity (e.g., Principal Mineral, Code Metal).
Others
- Lockheed Martin Ventures: Corporate venture arm of Lockheed Martin investing in dual-use technologies that align with defense prime priorities. Related ecosystem participant, providing strategic capital and procurement pathways similar to those J2 brokers for portfolio companies.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key risks5 records
Key highlights6 records
Customer concentration
J2 Ventures social profiles
Digital presenceJ2 Ventures financial estimates
Financial estimateRevenue estimate
Valuation estimate
J2 Ventures leadership team
Management profileNumber of profiles
Profiles15 records
J2 Ventures subsidiaries and ownership
Company hierarchySubsidiaries1 record
J2 Ventures funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
J2 Ventures M&A and investment
M&A and investmentM&A
Investments54 records
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about J2 Ventures
What does J2 Ventures do?
J2 Ventures is a venture capital firm that manages and deploys investment funds into early-stage dual-use technology companies serving both commercial markets and U.S. national security. Its flagship offering is the $250 million oversubscribed Brookhaven Fund, investing at Seed and Series A across advanced computing, biomedical engineering, cybersecurity, and infrastructure. Portfolio companies receive capital, strategic counsel, and direct access to government and defense networks through the firm's team of PhD scientists, combat veterans, practicing physicians, and former Defense Innovation Unit leadership.
Is J2 Ventures a public or private company?
J2 Ventures is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was J2 Ventures founded?
J2 Ventures was founded in 2021. It employs 1 to 10 people.
Where is J2 Ventures based?
J2 Ventures is headquartered in Boston, United States, in the North America region.
How does J2 Ventures make money?
One revenue line is on record: not disclosed.
Who are J2 Ventures's main competitors?
Broad incumbents on record are In-Q-Tel, Founders Fund, Andreessen Horowitz (a16z) — American Dynamism, Lux Capital, B Capital, General Catalyst and Khosla Ventures. Direct peers are Shield Capital and Overmatch Ventures. Lockheed Martin Ventures is listed as an others.
Does J2 Ventures have an API?
No public API is recorded for J2 Ventures.
What industry is J2 Ventures in?
J2 Ventures's product category is Venture Capital / Private Equity. Its primary akta.pro industry code is FSANAAAB, Early-Stage Venture Capital (Series A/B), with a secondary code of FSANAAAC, Late-Stage Venture Capital (Series C+). Its NAICS code is 52394 and its SIC code is 6282.