F
Friends & Family
We invest with and for people we trust. Long relationships over quick exits.
.capital
Infrastructure building creates fast, lasting value for the environment and society.
3fn builds and backs the physical foundations of a circular economy — the plants, flows and partnerships that turn waste streams into secondary raw materials.
What 3fn stands forThe name
Four letters, four commitments.
3fn is shorthand for the things that matter to us. Like an element in the periodic table, each one is a building block — stable on its own, stronger in combination.
1
2
F
Fit in Mind and Body
Clear heads and healthy lives make better decisions — for us and for the ventures we back.
3
F
Free
Independent capital, independent thinking. No mandates we don't believe in.
N
N
Nachhaltig
Sustainable, in the German sense of the word: built to last, for the planet and for the people on it.
Our thesis
Why infrastructure first.
Policies and pledges move slowly. A sorting line, a recycling plant or a reliable material flow starts delivering the day it is switched on. That is where we put our focus.
Fast impact
Physical assets displace primary raw materials immediately — measurable in tonnes, not in promises.
Lasting value
Infrastructure compounds. Once built, it keeps working for decades and anchors a whole ecosystem of suppliers and customers.
Environment and society
Secondary raw materials cut emissions and imports while creating skilled, local jobs. Both sides of the ledger improve.
“Infrastructure building delivers lasting value for the environment and society — fast.”
Contact
Let's build something that lasts.
If you develop, operate or finance circular-economy infrastructure, we would like to hear from you.
- office@3fn.capital
- Based in
- Vienna, Austria
- Web
- 3fn.capital · 3fn.at redirects here
David Mattersdorfer
Founder, 3fn.capital · Vienna
Who
Fifteen years in industrial waste and secondary raw materials.
David Mattersdorfer is an engineer from Montanuniversität Leoben who has spent his career turning industrial waste streams into secondary raw materials. He founded and sold Polymerstocklist to CYRKL, led CYRKL's international business as a partner, and today develops circular-economy projects for the metal, paper and plastics industries through his Vienna-based advisory firm MADANA.
He is an expert for Circular Materials at the Circular Economy Forum Austria, co-founded the Circular Economy Open Space community and teaches at FH Wiener Neustadt and FH BFI Wien. 3fn is where that experience becomes capital.