The online investment manager, which does not release results on its website, filed financial statements at Companies House.

Nutmeg reported a pre-tax loss of £9 million ($11 million) in 2015, up from £5.3 million the previous year, despite doubling its assets under management.

The firm did not give a figure for assets under management. Although turnover increased from £635,000 to £1.7 million over the year, operating expenses surged from £6 million to £10.8 million, partly due to higher marketing spend. Client numbers, meanwhile, grew by 50 per cent, though again an exact figure was not given.

Martin Stead took the helm in May this year after the firm's founding chief executive, Nick Hungerford, stepped down. In June, Bill Packman became chief operating officer and Catherine Prentke commercial director.

Stead said in a statement: “Nutmeg is on track with our mission to democratise wealth management and empower generations of investors. As is natural for an early-stage company, we have been investing heavily to establish ourselves and our brand, in line with an ambitious business plan. We now have an unparalleled, scalable platform; a highly experienced team; and a proven marketing model to win customers efficiently.”

“We’re currently tracking ahead of our targets for 2016. We’re proud of everything that we achieved last year, and I’d like to thank our investors, our employees and, most of all, our customers for their support in helping us to build a business that’s changing the world of investing for the better.”