Big banks that are major players in the mortgage servicing business reported generally solid gains in the market value of their MSRs during the fourth quarter, but the recent interest rate rally is already dampening the party. As a group, the 40 largest banks in the mortgage servicing business reported $2.00 trillion in 1-4 family servicing for other investors at the end of last year, an increase of $139.1 billion ( 7.5 percent) from