The Explorers Club has had the privilege of working with, learning from, and investing in several steward-owned ventures. Below are four of them. Each embodies the principles in this chapter differently, and each has something to teach us about what steward ownership looks like in practice.

CrowdBuilding (Netherlands): Community-led housing as non-extractive infrastructure

CrowdBuilding is a Dutch platform empowering citizens to develop community-led housing, and it’s steward-owned by design. The founding team made the explicit choice in April 2025 to hard-code their mission: financial and voting rights are separated to ensure the company can never be sold to an actor who would pivot it toward profit maximisation. In their own words:

“Our role is to help unlock systemic change, not to dominate or own the system.”

The steward ownership structure has become a strategic asset. It’s why governments and housing institutions trust them as neutral infrastructure for a movement, not just a vendor. And it’s part of why impact investors DOEN Participaties and Fair Capital backed them.

Karma Capital (Germany): steward ownership, applied to the investors themselves

Karma Capital is a Berlin-based hybrid: a regulated venture fund raising toward €25M that invests exclusively in steward-owned companies, paired with a non-profit that funds public-interest media and open-sources the legal infrastructure of the field.
It was founded by Sebastian Klein, who co-founded Blinkist, and after its ±$200M sale gave away 90% of his personal wealth, citing the toxic effects of extreme wealth concentration as his reason.

What makes Karma remarkable isn’t just what they invest in. It’s that they apply steward ownership to themselves. An independent Mission Steward Board governs the fund’s carried interest and guards its theory of change. The team runs on sociocratic principles.
Surplus carry flows automatically into the non-profit. The fund is a fractal: the structure it demands from
its portfolio, it imposes on itself.

The ripples reach further than the portfolio (Vyld, Wildplastic, WEtell, Neue Narrative).
Karma’s open-source term sheets and legal templates lower the barrier for every founder who comes after them, and their advocacy helped pave the way for a dedicated legal form for steward-owned companies entering the German federal coalition agreement. That’s what deploying at a leverage
point looks like: one fund shifting national corporate law.

“Steward ownership, by design, redistributes decision-making power away from the extractive
dynamics of the capital market and back toward people with genuine stakes in a company’s mission.”

Sumthing (Netherlands): Nature’s comeback story, structurally protected

Sumthing is a tech-for-good platform connecting donors with curated nature restoration projects, making impact tangible through drone and satellite footage. Certified B-Corp, recognised by the UN Decade on Ecosystem Restoration. And steward-owned from day one.

Their governance structure (three-tiered, with a Golden Share Foundation holding veto power over any sale or merger) makes their mission structurally irreversible. Rather than treating steward ownership as a constraint, the team talks about it as a story of integrity they’re proud to tell. It serves as a filter for aligned partners and investors, and as a trust signal for the restoration organisations they work with.

“If we all choose to do something, and together restore more nature than we lose each year, that comeback is within reach. But that only works when you feel connected to the impact you make. That’s why we make nature recovery visible and trackable.”

Exo Membranes (Belgium, KU Leuven spin-off): Deep-tech with a purpose lock

Exo Membranes, a KU Leuven spin-off founded by Dr. Rhea Verbeke and Laurent Hubert, develops patented epoxy membranes to treat industrial wastewater that today gets dumped or incinerated.

They chose steward ownership from day one, which is an unusual choice for a hardware start-up, and that’s exactly why they matter in this chapter.
Because there’s an honest question that often comes up, also in our own discussions:
what happens to a purpose lock in the capital-intensive moments of a company’s life?

Exo’s road to commercialisation is estimated at €8–10 million over 8–10 years. A capped return and a no-sale clause narrow the pool of investors willing to walk that road.Steward ownership is not the easiest structure precisely when a tech-driven venture needs capital the most.

Exo’s bet is that the lock is worth it: that without a structural safeguard, even the best-intentioned deep-tech company eventually faces pressure to be acquired by a player who may not share its values. They want to be the proof-of-concept that mission-driven deep-tech is fundable outside the conventional VC exit framework.