Over the latest five-year period, the group’s average actively-managed equity fund outperformed the sector average by more than 51%, according to research carried about by ratings firm FundCalibre.

When the index was first compiled in 2015, River and Mercantile secured 16th place before climbing to 5th place last year.

Darius McDermott, managing director of FundCalibre, said: “At a time when cheap passive funds seem to be getting all the focus, I think it is really important to highlight that a good actively-managed fund can really add value for investors.

“There are some great companies out there, from boutiques to global fund houses, which consistently outperform. Our index analyses the five-year performance of equity fund providers and the results show that, if you do your research, you can find some very good actively-managed funds that repeatedly do well for their investors.”

Six groups have been in the top 10 for three years running – Unicorn Asset Management, Stewart Investors, Old Mutual Global Investors, Baillie Gifford, SVM Asset Management and T. Rowe Price.

Eleven of the top 20 companies have 10 or more funds – so it’s not just the boutique firms with a small number of funds doing well. For example, Schroders has 43 qualifying equity funds, 88% of which have outperformed over five years.

Fidelity, with 38 qualifying funds, and Invesco Perpetual with 29 have also done well; 74% of Fidelity’s funds and 90% of Invesco Perpetual’s funds have outperformed over the same period.

Four mid to large-sized groups also had 100% of their funds outperform: Artemis (10 funds), JOHCM (12 funds), Premier (seven funds) and Stewart Investors (10 funds).

FundCalibre also noted that groups with a ‘value’ bias which have struggled in the past few years, have had a strong year, such as JOHCM and M&G.

You can see the full Fund Management Equity Index here, but below are the top 10: