Longrun Capital AB
Longrun Capital AB is a Stockholm-based climate-impact venture capital firm, the investment arm of Sweden's Ljungberg real-estate family, backing early-stage Nordic companies in clean energy, advanced materials, and the built environment. Founded in 2021, it writes seed cheques aimed at the most climate benefit per krona. As of 2026, (don't) Waste Water tracks one water company across two deals.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
Longrun Capital is the venture arm of the Ljungberg family, the Swedish real-estate dynasty behind Tagehus, and that lineage runs straight into the thesis. The built environment is responsible for roughly a third of global carbon emissions, so that is where Longrun goes looking. It backs early-stage Nordic companies in clean energy, advanced materials, and the technologies that take carbon out of construction.
Longrun Capital is not a water fund, and reading it as one would miss the point. Water turns up here the way it turns up across most of the climate economy, as the by-product of doing energy and materials well. The one water company (don't) Waste Water tracks, NSS Water, makes that concrete: NSS builds a tool that produces ultra-pure water for semiconductor and life-science manufacturing while cutting water use by up to ninety percent, an efficiency story before it is a water story.
Look across the rest of the book and the pattern repeats. Longrun Capital backed 3E Flow, which rethinks how buildings move hot water, and Drupps, which pulls usable water back out of industrial airstreams. Water at Longrun is always bolted to a building, a factory, or an energy system, never a standalone bet. That is the family-office discipline showing through: a small, concentrated portfolio where every cheque has to justify itself against a climate-per-krona yardstick.
What I watch with Longrun Capital is whether water graduates from a happy side-effect of its energy-and-materials thesis into something it names on purpose. For now it is a climate fund with a real-estate backbone that happens to own some of the most interesting water-efficiency technology in the Nordics, and NSS Water is the name to know it by.
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 · 1 water companies
Invests alongside
Highlighted = profiled on (don't) Waste Water.
Frequently asked
- What does Longrun Capital invest in?
- Longrun Capital backs early-stage Nordic companies in clean energy, advanced materials, and the decarbonisation of buildings and construction. Within water, (don't) Waste Water tracks one holding, NSS Water, whose tool makes ultra-pure water for high-tech manufacturing while cutting water use by up to ninety percent.
- Is Longrun Capital a water fund?
- No. Longrun Capital is a climate-impact venture firm focused on energy and advanced materials, mostly tied to the built environment, not a dedicated water fund. It holds one water company (don't) Waste Water counts, NSS Water, alongside water-adjacent bets like Drupps and 3E Flow inside its broader climate thesis.
- Who runs Longrun Capital?
- Longrun Capital was founded in 2021 by Cristina Ljungberg and Johan Frenckner as the Ljungberg family's climate initiative. Founding Partner Johan Frenckner leads the investing, with Senior Investment Partner Matilda Knuts, who joined in 2022 from a banking career at Barclays and Nordea.
- Where is Longrun Capital based?
- Longrun Capital is headquartered in Stockholm, Sweden, and invests mainly across the Nordics. Founded in 2021 as the venture arm of the Ljungberg real-estate family, it made its first investment outside Sweden in 2025 while keeping its focus on Nordic climate technology.
- Is Longrun Capital the same as Long Run Capital?
- No. Longrun Capital AB is a Stockholm-based climate-impact venture firm tied to Sweden's Ljungberg family. It should not be confused with similarly named investors such as the US-based Long Run Capital; the Swedish Longrun focuses on Nordic energy, advanced-materials, and built-environment startups.