After at least 2 days of (or more) of relatively disconnected markets (i.e. trading levels weren't reliably following any single market mover), today is starkly different.  There's one single elephant in Friday's room, or perhaps it's a small blue birdie.  

A Trump tweet late yesterday was all it took to start a snowball of massive bond-buying demand.  Simply put, Trump "announced" new tariffs on Mexico in much the same way he did for China on May 5th.  Stock prices and bond yields reacted immediately in the overnight session by moving sharply lower.  The domestic trading session saw both hold relatively steady--and even reverse course slightly--until European markets closed.  After that, stocks and rates slipped to new lows for the day.

For the bond market, yields hit new lows not just for the day, but also for the week, month, and year.  We now have to go back to 2017 to see anything lower.  The ability of this move to continue is only limited by the persistence of inflammatory trade-related headlines and the weakness in any of next week's economic data.