The 10yr TSY note yield is -0-07 at 101-16 yielding 3.446%....higher from opening levels, testing the upper boundaries of  support (as discussed this morning).  

 While "rate sheet influential" benchmark yields rose quickly, "rate sheet influential " MBS coupons did not react the same way...instead prices fell only marginally and yield spreads tightened.

The FN 4.0 is -0-04 at 98-06 yielding 4.187% and the FN 4.5 is trading -0-03 at 100-28 yielding 4.395%. The secondary market current coupon is 4.322%. The Current Coupon is +87/10yr TSY and +68/10yr swap.

If the 10yr breaks through 3.45% support, expect MBS prices to fall further...REPRICES FOR THE WORSE ARE A RISK