The same old pattern played out today where MBS weren't able to keep solid pace with Treasury movement.  This is one of those "for better or worse" kind of things.  MBS tend not to gain as much ground as Treasuries when bonds are rallying (like yesterday), but in return, they usually avoid losing as much ground when bond yields are moving higher.   

10yr yields ended the day more than 5bps higher (or half a point lower in terms of price).  Fannie 3.0 MBS coupons were only 1 tick (0.03) lower by comparison!

Some of the overall bond market weakness was intact right at the start of the day after trade-related headlines did some damage overnight.  After a modest recovery during the first few hours of the domestic session, bonds weakened steadily heading into the afternoon hours--perhaps with some apprehension about the 10yr Treasury auction.

The auction results were relatively decent, but not strong enough to suggest that the bond market's afternoon weakness wasn't warranted.  From there, the release of the minutes from the Fed meeting 3 weeks ago did very little to change momentum.  A trade headline (China said a deal was less likely) hit stocks and helped bonds late in the day, but not in any significant way.