Hargreaves Lansdown has seen its assets under administration increase by 4 per cent to £82bn in the three months to the end of September.
Of this increase in assets, £1.5bn is attributed to net new business while £1.3bn is due to market movements.
This is slower growth in assets than the company has seen in recent months.
In the same three month period last year, Hargreaves Lansdown increased its assets by more than 9 per cent and by 10 per cent in the four months to the end of April 2017.
The FTSE 100 company increased its client base by 30,000 during the period, taking its total active client numbers to 983,000.
Chris Hill, chief executive of Hargreaves Lansdown, said: “I'm pleased to report a solid start to the new financial year for net new business and revenue.
“We continue to place clients at the centre of what we do and our relentless focus on the level of service that we provide is enabling both existing and new clients to save and invest with confidence.”
Net revenue for the period was £104.1m, up 15 per cent on last year.
Of its assets under administration, £46.6bn are in funds, £27.1bn are in shares and £8.8bn are in Hargreaves Lansdown’s own funds.
The Bristol-based company said it also benefited from significant transfer activity relating to operational issues on a competitor platform, which it has not named.