Everybody knows Bank of America (BAC 1.40%) is swimming upstream in terms of profitability. Last year, the nation's second largest lender by assets earned $4.2 billion. Meanwhile, JPMorgan Chase (JPM 1.68%) and Wells Fargo (WFC 1.20%) reported net incomes of $21.3 billion and $18.9 billion, both of which were records for the respective companies. In the video below, Motley Fool contributor John Maxfield identifies one of the primary explanations for this disparity: mortgage-servicing rights related to toxic mortgages.