Total assets held on UK investment platforms increased by 21 per cent in 2017, according to data compiled by Fundscape.
Assets held on platforms now account for £592bn, which represents growth in money terms of £102.9bn.
A total of £352bn, or around 59 per cent of the total of all platform assets are administered by financial advisers, according to the research.
Gross sales were just less than £33bn in the final three months of 2017, the second best quarter ever, according to Fundscape, despite the continued political uncertainty in the UK.
Isa assets held on platforms at the end of 2017 totalled £155.8bn, with self-invested personal pension assets accounting for £194.1bn, while defined contribution (DC) pensions contributed £359bn.
The growth in total platform assets continues to be driven by the Sipps and the wider pension market, which accounts for 33 per cent of the total assets on platforms. In 2017, 63 per cent of the total net inflows onto platforms during the year came from pension customers.
Fundscape estimated two thirds of the pension assets are in accumulation - the saving phase - and one third in decumulation - the spending phase.
UK investors remain keen on the domestic market, according to data from Lloyds Private Bank.
It compiled a survey of its clients, conducted in February, which showed strong investor optimism about the outlook for UK equities.
A net 15 per cent of respondents were positive on the outlook for the asset class, while investors were most negative on Eurozone shares, with a net 35 per cent expressing negative sentiment towards the asset class.
Investors were also negative towards US equities, with a net 5 per cent of Lloyds clients negative about the outlook for Wall Street.