# Thominvest

Thominvest is a Single Family Office based in Helsinki, Finland.

## Overview

- **Organization type:** Single Family Office
- **Headquarters:** Helsinki, Finland
- **Region:** Europe
- **Address:** Kalevankatu 12, 00100 Helsinki, Finland
- **Founded:** 1911
- **Assets under management:** 105 (Altss estimate)
- **Website:** thominvest.fi
- **LinkedIn:** https://www.linkedin.com/company/thominvest

## Regulatory record

- **Reports private funds:** No

## About

Thominvest traces its roots to 1911 when W.G. Thomé established a forestry office in Finland. Leo and Kata Jouhki acquired the business through family ties and expanded it into timber trading and shipping. Fifth-generation descendants continue to own and direct the firm through Thomasset Oy and related holding structures. The portfolio mixes listed securities, direct co-investments, real-estate holdings and venture positions. Confirmed co-investors include Alexander Ehrnrooth’s Nidoco AB and Gorilla Ventures Oy in CollectiveCrunch, a data-analytics company focused on forestry. Additional exposure spans Europe, North America and selected markets in Asia and Africa. The firm also maintains allocations to hedge funds and special-situations vehicles. Mats Söderström serves as Managing Director while Tarja Japola handles back-office operations. The team occupies a single office at Kalevankatu 12 in central Helsinki. Johanna Jouhki participates in Perheyritysten liitto, the Finnish family-business network. No material operational announcements have surfaced in the past twenty-four months. Ownership remains concentrated within the Jouhki family through Thomasset Oy, with Juha Jouhki acting as chairman. This closed structure limits external capital and keeps decision rights inside the founding lineage rather than delegating to outside managers or multi-family platforms.

## Sectors

- Circular Economy
- Digital Health
- FinTech
- ClimateTech
- Mobility & Transportation

## People

- Mats Söderström — Managing Director
- Tarja Japola — Back Office Manager

## Questions

### Who runs investment decisions at Thominvest?

Mats Söderström serves as Managing Director and leads the investment process. Juha Jouhki chairs the parent holding company Thomasset Oy. Family principals retain final authority on commitments.

### How does Thominvest source proprietary deal flow?

The firm relies on long-standing relationships within Finnish industry and forestry networks. Co-investments such as CollectiveCrunch have come through partners including Nidoco AB and Gorilla Ventures Oy.

### Does Thominvest participate in fund commitments or only direct deals?

The office uses a mix of direct co-investments, SPVs, fund-of-funds vehicles and hedge-fund allocations. Direct positions remain the primary focus for early-stage opportunities.

### What investment stages does Thominvest typically target?

Activity centers on seed and early-stage rounds. The firm also holds public-market securities and real-estate assets that require longer holding periods.

### Does Thominvest maintain philanthropic structures?

The family supports Aalto University and the John Nurminen Foundation. These vehicles operate separately from the investment company.

### What is Thominvest’s known posture on co-investments alongside external GPs?

The firm has joined external partners in at least one documented transaction, CollectiveCrunch, alongside Nidoco AB and Gorilla Ventures Oy in 2021.

## Related profiles

- [Avantia](https://altss.com/profile/avantia)
- [Glastad Holding](https://altss.com/profile/glastad-holding-glastad-family-office)

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Last updated: 2026-08-10T15:54:10.904Z

Canonical page: https://altss.com/profile/thominvest-jouhki-family-office

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