Jupiter Asset Management saw net outflows of £4bn during 2020 - though its assets under management reached a new high of £58.7bn.
According to Jupiter's results for 2020, the increase in assets was primarily down to the acquisition of Merian Global Investors, which completed during the year and added £17bn to the company's assets.
As far as the outflows were concerned, Jupiter said these were "heavily concentrated" in the first quarter as investors sought liquidity and the company said its funds recorded three consecutive quarters of positive net inflows after that.
Andrew Formica, Jupiter's chief executive, said: "This is a year where we made significant progress against our strategic objectives and laid strong foundations for future growth, despite the disruptive impact on financial markets and businesses brought by Covid-19.
"Against a backdrop of strengthening investor sentiment and improved momentum as we turn the corner in the battle against Covid-19, I am confident that Jupiter is strongly positioned for future growth."
Jupiter posted a pre-tax profit of £132.6m, fell 12 per cent on 2019, primarily due to the costs of the Merian acquisition and integration.
Addressing the Merian acquisition, Formica said: "This transformational deal has expanded our product and geographic offering while reinforcing our position as a market leader in UK retail.
"Financially it has exceeded our expectations, delivering greater than expected synergies and already making a significant contribution to group profits.
"While more time is needed to stabilise flows from certain products, these near-term challenges were well-anticipated and factored into the terms of the deal, giving substantial protection to our shareholders."
Last month it emerged Jupiter was proposing to make up to 90 - or 16 per cent - of its staff redundant in a bid to become "more agile".
During 2020 Jupiter said it expanded its environmental, social and governance offering and embedded these processes through its culture and funds.
Jupiter said it would invest "selectively" if it saw opportunities for organic growth during 2021.