First off, any examination of price movement today requires the caveat that none of it has any implication beyond the next few hours. While volume is higher than yesterday, it’s still extremely low overall and staffing levels are very light.
Bond markets were weaker overnight as Europe released some pent-up bearishness after 2.5 days off. Treasuries followed but were able to turn the corner heading in to the domestic session. MBS have improved steadily since then and that’s all there is to it.
It would be a mistake to look for any cause and effect or to infer any sort of meaning behind any price movement this week, unless that meaning is the absence of meaning.