MBS CLOSE: Falling more sharply into the close

4.5's have now retraced ALL of their gains on the day and we are right back where we started at 101-19.  You know what that means!  you'll potentially end up with worse pricing at the end of the day than the beginning.  Beware of slight additional negative reprice potential.  Although keep in mind that treasuries have performed similarly and we are not negative on the day.