The acquisition of fellow wealth manager Speirs and Jeffrey has helped Rathbones fended off market turmoil at the end of the year and boosted the assets under management of Rathbones during 2018.
In results for 2018 posted, Rathbones says total funds under management increased by 12.8%, from £39.1bn to £44.1bn in the year, despite the FTSE falling 12.5% over the period.
These assets generated a net income of £275.3m, compared with £254m for 2017. The acquisition of Speirs and Jeffrey contributed £8.7m.
The company recorded a profit before tax of £87.4m, up 4.7% on 2017.
Rathbones says that though it has absorbed an 11% underlying increase in operating expenses through the acquisition and adding additional capacity, but profits margins remained around 30%. Pre-tax profit increased 4.1% from £58.9m to £61.3m.
Mark Nicholls, Rathbones' chairman, said: "Brexit is likely to be one of the most significant political and economic events to impact the United Kingdom in our lifetimes. The lack of consensus on the United Kingdom's strategy for the future creates unprecedented levels of uncertainty and the longer term implications will not be clear for some time.
But he added: "As a UK business with no operations in other European Union countries, no material dependencies on goods or people from other European Union countries and a predominantly UK client base, we anticipate that the operational impacts on our business will be relatively small."
Chief executive Philip Howell, who is retiring in May and will be succeeded by group finance director Paul Stockton, said: "The year was characterised by some additional demands placed upon the business. On the one hand, we needed to adapt to new regulatory regimes and navigate increasingly complex investment conditions. On the other, we continued to progress our five-year strategic initiatives and completed the most significant acquisition in our history. Our positive financial results despite this significant level of activity demonstrate the resilience of our business."
Wealth managers have had a difficult period. They have struggled to shore up assets in recent months as choppy investment markets have taken a toll on their assets and cut fee income and face high competition for customers.