Mortgage backed securities (MBS) closed flat today at 104.03 having opened well above Friday's level and surged above resistance formerly offered by the 50 and 100 day moving averages. This good day in MBS markets has pushed the 30 year fixed conforming rate down to 4.50%. The jumbo, which does not necessarily track movement in MBS bonds, was available at an attractive 4.375% for a $1,000,000 loan.