MCJ (MCJ Collective) Research
Investment Thesis
MCJ is a climate-focused venture firm that backs "extraordinary founders leading the transition of energy and industry and solving the inevitable impacts of climate change." The firm describes its mission as discovering and investing in startups rewriting industries to be cleaner, more profitable and more resilient. Two themes run through its recent work, which it names in the Fund II announcement: the energy transition and climate resilience. Because the firm expects societal demand for computing and power to keep rising rather than shrink, it is especially drawn to clean solutions that meet increasing power demand: nuclear and fusion, geothermal, solid-state grid hardware, long-duration storage, and software that helps utilities and developers plan and dispatch.
MCJ began life in 2019 as My Climate Journey, a podcast and community founded by Jason Jacobs, and grew into a venture fund with an operator and LP network around it. After Fund II closed in September 2024 the investing entity became simply "MCJ" (web address mcj.vc), and "MCJ Collective" now refers to the vetted member network. That network, plus a media platform (the Inevitable podcast, formerly My Climate Journey, and a newsletter with 35K+ subscribers), is the firm's stated differentiator: it has helped portfolio companies hire 50+ people from the network and facilitated hundreds of introductions.
Stage Focus and Check Size
Third-party profiles describe MCJ as investing from pre-seed to Series A, with checks of roughly $500K to $5M. The firm's own announcements are consistent with that: it led the DaisyChain Energy seed, and participated in the $10M Red Metals seed (led by Gigascale Capital) and the $46M Light Series A (led by Matrix, with MCJ and BoxGroup). The portfolio pages tag several companies as seed (Hammerhead AI, Pravah, Reservoir, Unlimited Industries) and several as Series A (DG Matrix, Standard Nuclear). Check size is not stated on the firm's site, so the range above is a lower-confidence estimate.
Lead Tendency
MCJ both leads and follows. It led the DaisyChain Energy seed round, but in 2026 announcements such as Red Metals and Light it participated alongside a named lead. It is best treated as a flexible early-stage investor that often takes a meaningful position and a supporting role in syndicates.
Recent Activity and Fund Status
Fund II closed in September 2024 at $80.6M, taking total assets under management above $115M across two funds. The fund is actively deploying: the portfolio page shows a steady cadence of new investments through 2025 and 2026, including Pacific Fusion, Fourier, Mantel, Exowatt, LGND, Light, Rodatherm, Aalo Atomics, Hammerhead AI, Unlimited Industries, Archimetis, Standard Nuclear, Terrawise, Pravah, DG Matrix and Face Plant (the most recent listed in February 2026). Newsletter posts in 2026 announce investments in Red Metals (June 2026), Light (Series A, September 2026), DaisyChain Energy and DG Matrix.
Portfolio Highlights
The portfolio is broad, with roughly 90 companies listed across Energy, Built Environment, Mobility and Transport, Industrial and Manufacturing, Carbon, Food, Agriculture and Land Use, Financial Services, Resource Use and Circularity, and Management and Reporting categories. Notable names include Crusoe (clean computing infrastructure), Heirloom (direct air capture), Charm Industrial, Pacific Fusion, Base Power, SPAN, Solugen, Sublime Systems, AMP Robotics, Enode, LevelTen Energy, Zanskar, Aalo Atomics, The Nuclear Company, Standard Nuclear and Avalanche Energy. The firm tags companies as "atoms" or "bits", reflecting a mix of hardware and software bets.
Team
- Cody Simms, Managing Partner: former SVP of Climate and Sustainability at Techstars and an investing partner in Techstars institutional funds; earlier product roles at StumbleUpon and Yahoo; host of the Inevitable podcast.
- David Aronoff, Chairman and Managing Partner: former General Partner at Flybridge (from 2005) and earlier at Greylock Partners; board member at Draper Laboratory.
- Yin Lu, Partner: investments and post-investment founder support; formerly GM of Khan Academy international and early Coursera team.
- Thai Nguyen, Partner: joined in 2020; ex-Intuit product and business development, Luxe, and automotive mobility consulting; activates corporate partners.
- Jason Jacobs, Founder and Venture Partner: founded MCJ; moved to a venture partner role in 2024.
- Courtney Flynn (CFO), Jenn Beening (Marketing and Content) and Lauren Miller (Talent) support the platform.
Decision Process
MCJ is a partnership led by two managing partners, Cody Simms and David Aronoff, with partners Yin Lu and Thai Nguyen. The firm does not publish its decision timeline, so none is recorded here.
Founder Preferences
The firm looks for founders solving a real problem in energy, industrial decarbonization or climate resilience who can use the member network for hiring, customers and corporate partnerships. Founders can pitch via the site, and the firm runs a talent system and events to feed portfolio companies.
Geographic Focus
The portfolio is primarily US-based, with international holdings such as BasiGo (Kenya), BOLT (India), Zeno (emerging-market micromobility), Hoxton Farms (UK) and Odyssey Energy (emerging markets). Headquarters location is not stated on the website.