MBS have been declining steadily throughout the morning with additional weakness seen after the conclusion of the Fed's MBS buying (only 2 operations per day now, with both concluding before noon).  

2.5 UMBS are now down 5 ticks (.16) from the morning's highs and an eighth of a point on the day.  Some of the jumpier lenders could be considering negative reprices, but the average lender would need to see several more ticks of weakness.