FABRICE COFFRINI/AFP via Getty Images Swiss bank UBS posted a 54% jump in fourth-quarter net profit to $6.6 billion on Tuesday.Although the bank smashed analyst expectations, UBS cautioned on the economic outlook for 2021.UBS' fourth-quarter earnings are the first results under new CEO Ralph Hamers' leadership.Sign up here for our daily newsletter, 10 Things Before the Opening Bell.Swiss lender UBS posted a 54% rise in fourth-quarter net profit on Tuesday, beating analyst expectations, driven by an increase in income for the bank's super-rich clients.Full-year net profit jumped to $6.6 billion, well above analyst expectations of $5.9 billion.The world's largest wealth manager doubled the size of a previous share repurchase program, saying it expects to buyback about $4.5 billion of shares over the next three years.