MBS are very close to their February 5th levels, which were the best since the morning of December 18th before the Fed announcement (and dot plot) caused a big sell-off. Today, it's econ data that's contributing to the third day in a row of moderate gains. Specifically, S&P Services PMI dropped sharply to levels that are consistent with economic contraction, significantly undershooting expectations. Bonds responded immediately with MBS adding to overnight gains for a total of a quarter point day over day.
