Everybody knows Bank of America (NYSE:BAC) is swimming upstream in terms of profitability. Last year, the nation's second largest lender by assets earned $4.2 billion. Meanwhile, JPMorgan Chase (NYSE:JPM) and Wells Fargo (NYSE:WFC) 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.