One Small Planet
One Small Planet is a Boulder, Colorado vital-capital group founded in 2020 by Will Peterffy. The impact-investing family office backs regenerative technology from seed to Series A, with water technology among its Fire Fund's core ecosystems. As of 2026 it has backed two water companies.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
One Small Planet is the rare climate fund that puts impact ahead of return in writing: its venture arm, the Fire Fund, says it weighs each investment first as a Ripple of Impact in the world and only second as a financial return. The group is the vital-capital vehicle of Will Peterffy, who studied environmental science in Boulder, spent a decade in regenerative agriculture, then built Interactive Brokers' socially-conscious IMPACT trading platform before founding One Small Planet in 2020.
One Small Planet backs regenerative-systems technology from seed to Series A across four ecosystems: regenerative systems tech, sustainable materials, carbon sequestration and reforestation, and water. The water thread is not incidental. The Peterffy family foundation that Will runs with his sisters is built around the health of the world's water systems and Indigenous water stewardship, and that conviction carries over to the venture side.
On the water side specifically, One Small Planet has backed two companies that share a thesis more than a sector: instrument the physical world so it wastes less. LAIIER prints thin adhesive sensor tape that catches leaks before they become floods; Verdi bolts solar-powered, cloud-connected controls onto the irrigation valves already sitting in farmers' fields. Both are seed-stage, both closed in 2025, and on each round One Small Planet sat alongside dedicated water funds like Burnt Island Ventures and Ponderosa Ventures.
For a newcomer, One Small Planet is a useful tell about where impact-first capital is heading: into the connective tissue between food, land, and water rather than a single water silo, funded by a family that made its fortune in financial markets and is now trying to make markets answer to ecology. As of 2026 the Fire Fund is still writing seed and Series A cheques against that idea.
Water Commitment Score
Compiled from official filings, third-party records, and direct intelligence from investors and founders, in Leviathan · recomputed monthly · as of Jun 2026.
How they invest
Portfolio · 2 water companies
Invests alongside
Highlighted = profiled on (don't) Waste Water.
Frequently asked
- What does One Small Planet invest in?
- One Small Planet invests in regenerative-systems technology from seed to Series A, spanning sustainable materials, carbon sequestration and reforestation, and water. Its venture arm, the Fire Fund, weighs each deal first by ecological impact and second by financial return, backing founders building systems that work with nature rather than against it.
- Who runs One Small Planet?
- One Small Planet was founded in 2020 by Will Peterffy, son of Interactive Brokers founder Thomas Peterffy and the architect of that firm's socially-conscious IMPACT trading platform. Chief Investment Officer Jack Wielebinski runs the Fire Fund venture arm, and Bradley Smith serves as Managing Director. The Boulder, Colorado group is the family's vital-capital vehicle.
- Is One Small Planet a water investor?
- One Small Planet is a broad regenerative-technology investor, not a dedicated water fund. Water technology is one of four core ecosystems for its Fire Fund, sitting beside sustainable materials, carbon and reforestation, and regenerative systems. Newcomers should not confuse it with single-sector water venture firms.
- Where is One Small Planet based?
- One Small Planet is based in Boulder, Colorado, where founder Will Peterffy studied environmental science before a decade in regenerative agriculture. The group operates as a vital-capital family office that combines venture investing through its Fire Fund with land stewardship, philanthropy, and community programs under one roof.
- How many water deals has One Small Planet done?
- As of 2026, One Small Planet has backed two water companies, LAIIER and Verdi, across two seed-stage rounds tracked in Leviathan, the most recent in 2025. Both sit inside the Fire Fund's water-technology ecosystem, which the firm treats as one strand of a broader regenerative thesis.