SIS Ventures
SIS Ventures is the impact-investment venture arm of Social Investment Scotland, an Edinburgh fund for early-stage Scottish companies. It backs businesses whose work advances the UN Sustainable Development Goals. As of 2026 it is managing its existing portfolio rather than making new investments, and the Leviathan database tracks one water-relevant holding, circular-economy biotech MiAlgae.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
SIS Ventures is the venture-capital arm of Social Investment Scotland, the Edinburgh charity that has been lending to social enterprises since 2001, and it was built in 2018 by Thomas Gillan as Scotland's first impact-focused VC fund. The idea was simple and, at the time, slightly contrarian: take the early-stage equity playbook and point it at companies whose social and environmental mission is written into the business rather than bolted on. Its vehicle, the Impact First fund, backs young Scottish companies whose work maps to the United Nations Sustainable Development Goals, the global checklist of targets on things like clean water, health and responsible production.
SIS Ventures today is run by executive director Arran Dewar, a chartered accountant who joined from venture-philanthropy outfit Inspiring Scotland, inside the wider Social Investment Scotland group led by chief executive Alastair Davis. As of 2026 the fund is not making new investments and is focused on managing the companies it already backs, a deliberately quiet phase that its own website and LinkedIn both spell out plainly. For a newcomer that is the single most useful thing to know: this is a portfolio to be stewarded right now, not an open cheque-book.
SIS Ventures is an impact generalist, and water reaches its portfolio through one company rather than any dedicated mandate. The single water-relevant name the Leviathan database tracks is MiAlgae, a Scottish biotech that grows microalgae on the by-products of whisky distilling to make omega-3 without stripping it from wild fish, a circular-economy bet that lands squarely on the UN goal of life below water. SIS Ventures backed MiAlgae across two funding rounds. Whether more water names follow will depend less on any water mandate and more on where Scotland's next mission-led founders decide to point their companies.
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 SIS Ventures invest in?
- SIS Ventures invests equity in early-stage Scottish companies whose social and environmental mission advances the UN Sustainable Development Goals, through its Impact First fund. It is an impact generalist rather than a water specialist; in the Leviathan database its one water-relevant holding is MiAlgae, a circular-economy biotech making sustainable omega-3.
- Is SIS Ventures still making new investments?
- SIS Ventures is not currently making new investments. As of 2026 the fund states on its own website and LinkedIn that it is focused on managing its existing portfolio rather than deploying into new companies. A newcomer should read it as an active portfolio to steward, not an open fund seeking deals.
- Who runs SIS Ventures?
- SIS Ventures is led by executive director Arran Dewar, a chartered accountant who joined from venture-philanthropy organisation Inspiring Scotland in 2023. It was founded in 2018 by Thomas Gillan and sits within the Social Investment Scotland group, the Edinburgh impact-investment charity led by chief executive Alastair Davis.
- Where is SIS Ventures based?
- SIS Ventures is based in Edinburgh, Scotland, and is regulated by the UK Financial Conduct Authority. Founded in 2018 as the venture arm of Social Investment Scotland, it backs early-stage companies based in Scotland that pursue measurable social and environmental impact alongside a financial return.
- What is the difference between SIS Ventures and Social Investment Scotland?
- Social Investment Scotland is the parent: an Edinburgh charity and lender that has financed social enterprises since 2001. SIS Ventures is its venture-capital subsidiary, launched in 2018 to make equity investments in early-stage, high-growth impact companies. The group lends; SIS Ventures takes equity stakes in mission-led startups.