Liontrust's assets under management rose by £723m in the six months to the end of September, driven largely by inflows into the sustainable investment fund range bought from Alliance Trust.
Investors have poured £900m into those funds since Liontrust bought them in April 2017 and the strategies had assets of £3.4bn at the end of September.
Liontrust said: "An increasing number of institutions and investors realise sustainable is a proven investment style and an ever growing number of people care about how they make their money as well as how much money they make.
"We are confident the [assets] will continue to increase given the experience and long track record of our sustainable investment team, their extensive knowledge and expertise and the integration of [ethical, social and governance] with their investment decisions.
Chief executive John Ions said the company’s UK Special Situations fund was the fourth best selling fund to UK investors in the third quarter of 2018, and was now £3.9bn in size.
Liontrust’s total assets under management on 30 September were £12bn, but the market volatility since then has saw assets drop to £11.5bn by November 19.
Mr Ions said: "Increased volatility, which we have seen in equity and bond markets, is usually a positive for us. Investors become more discerning and look for fund managers who have a robust process, a good track record of being able to handle such an environment and of superior stock selection.
"With the gradual withdrawal of central bank support, for example, active management and having the ability to be flexible will become increasingly important when investing in bond markets."
The company posted a net profit of £14.5m, an increase of 21 per cent on the same period in 2017.
Liontrust also announced Adrian Collins would retire as chairman early next year after nearly a decade in the role and be replaced by the chairman of the company's audit committee, Alastair Barbour.