Bonds managed to bounce back a bit as stocks sold at the 930am NYSE open, but the gains have now reversed.  At first glance, it is odd to note that MBS are leading the weakness despite 10yr Treasuries facing down an auction at 1pm.  It's less odd when we consider the Fed's MBS buying operation just ended (and weakness has been common after Fed buying sessions with heavy supply).  While today's 30yr fixed UMBS supply wasn't as high as yesterday's (I'm using the word "supply" to refer to the amount offered by sellers during the Fed operation), it is still nearly 3 times higher than the Fed's max amount.  Contrast that to the other operation which is only about 2x higher.

2.5 UMBS are currently an eighth of a point off their highs, and 2.0 coupons are almost a quarter point lower.  Technically, this is enough for a modest amount of reprice risk, but only from the jumpiest lenders.  Even then, with the morning seeing much weaker prices, it's unlikely that lenders set rates with the highs of the day in mind, and they only could have done so after 10:15am ET. 

All that to say that a negative reprice or two couldn't be completely ruled out, but we haven't seen quite enough weakness for it to be a serious concern.