Nutmeg's losses have continued to grow, reaching £12.3m for 2017.
The robo-adviser, which was founded in 2011, has yet to make a profit and saw its losses increase by £4m over the course of last year.
While the company's turnover increased by £2m to £4.5m, its operating expenses increased by more than double this, going up from £11.9m in 2016 to £16.9m in 2017.
Martin Stead, the company's chief executive, said Nutmeg was continuing to grow "significantly", passing £1bn of assets and ending 2017 with more than 50,000 customers.
He said: "Despite an increase in competition, Nutmeg remains, by a significant distance, the largest European pure online digital wealth manager, and one of the fastest growing wealth managers in the UK.
"Nutmeg continues to invest in the business and this investment is reflected in the trading loss reported in the statement of comprehensive income."
Mr Stead said Nutmeg continued to be backed by long-term investors who were committed to supporting the company become a "major global player of scale" and it has already entered into a partnership to explore expansion in the Asian market.
Nutmeg’s backers include Schroders, Pentech, Balderton Capital and Armarda Investment Group.
Mr Stead said: "The business is also focused on new growth opportunities beyond its existing digital wealth management proposition in the UK. Specifically, it is leveraging its financial advice licence to further develop its online financial advice proposition."
Nutmeg has said it may need more cash injections from its financial backers, but said it has a "reasonable expectation" of receiving this additional funding.
Back in 2016, a report into the sector claimed robo-advisers could take up to a decade to make a profit from their clients.
Analysis from IRN Consultants highlighted each new robo-advice customer signed up is losing the company £162.50 on average in the first year and only making £17.50 in subsequent years.
This would mean that client would have to be retained for the better part of a decade just for the company to break even from them - assuming the robo-adviser's business model doesn't change.
Mike Pendergast, an adviser with Zen Financial Services, said the problem for robo-advisers, like financial advisers, was customer acquisition.
He said: "It depends if they feel they can make money out of customers in the long term so there may be losses in the first few years. But customers are more and more mobile these days, especially if they are going direct."