Although markets stumbled in the final few months of the year, funds under management (FUM) at wealth management group Rathbone Brothers continued to their serene march higher.Total FUM of £27.2bn at 31 December was a 3.4% increase in the fourth quarter and a 23.6% rise from a year before, with the FTSE 100 down 2.7% over 2014.The FTSE 250 group said it expected investment markets to "continue to be volatile" in 2015, but said its outlook remained positive."We continue to pursue our growth objectives, whilst responding to ongoing changes in the industry, and investing to ensure that we continue to have the right level of infrastructure and resources."Rathbones enjoyed £327m of net inflows in the quarter, raising the total for the year to £4bn including acquisitions, and its investment management division (RIM) grew FuM 3.1% to £24.7bn, with acquisitions adding 0.9%, net inflows 0.4%, and performance 1.8%.Broker Canaccord said this update supported its view of Rathbones as a "value compounder"."This FuM update gives us confidence to set a February 2016 target price based on our full year 2016 forecast. Our new 2,310p target price is 6.9% above the 2,160p target price we set in May 2014, which was based on 17.0 times full year 2015 expected earnings per share. Our new target price is 16.0x our FY16e EPS."At 2,043p, Rathbone shares are trading on a 2.5% dividend yield and provide scope for a 16% total shareholder return over the next 13 months."