As Nucleus's rivals were hit with technology problems the platform that was launched by financial adviser saw assets under administration increase.
Total assets at the end of 2018 on the platform, which was launched in 2006 by a group of seven financial adviser firms, were £13.88bn, compared with £13.57bn at the end of December 2017.
But while 2017's total was helped by £296m of growth as a result of positive stock market movements in that year, in the 2018 calendar year market volatility meant assets on the platform were £994m less than would otherwise have been the case.
The number of financial advisers actively using the platform at the end of 2018 was 1,396, an increase of 6 per cent on the previous year.
The total number of customers using the Nucleus platform at the end of 2018 rose to 93,715.
Nucleus floated on the stock exchange via an initial public offering (IPO) in July 2018, with a market capitalisation of £140m.
The shares came to market at a valuation of £2.39, but today (January 28) trade at £1.58.
Nucleus's growth came as rivals Aviva and Aegon were hit by issues with replatforming.
The platform was unavailable for six days in January 2018. Clients were later unable to receive tax certificates, or income, and reported long waiting times on the phone when dealing with the firm.
Aviva's extensive list of problem was similar to that of the Aegon platform whose head of platform, Richard Denning, left in September to "have a break from corporate life".
David Ferguson, founder and chief executive of Nucleus, said: "Nucleus has grown strongly in recent years and, despite the challenging market backdrop, I am pleased to report our twelfth successive year of growth in AUA, adviser users and customer numbers.
"Having listed the business in 2018 and reorganised our major outsourcing relationships in the fourth quarter of the year, we are now focused on accelerating our growth within the sector."
david.thorpe@ft.com
