This is more of a heads-up than a full-blown alert. Bonds are generally sideways on the day, but rallied mildly in the AM hours to the highs of the day around 11:20am. Since then, there's been gradual selling to the tune of an eighth of a point in MBS.
Most lenders don't prices as late as 11:20am and are thus not at much risk for considering reprices. That said, there are some past examples of a lender or two repricing in similar scenarios.
