• Brexit leads European panic
• European panic leads bond yields lower
• Europe gets their fill just after 10am and markets reverse
• US bond markets bounce back after European close
• Consumer Sentiment inflation expectations helped extend the rally just a bit

Be it Brexit fears or "global growth concerns," panic is in the air.  Panic has driven European yields to all-time lows for the past 4 days.  It has also pulled US bond market volume higher for the past 3 days.  Just today, it deposited 10yr yields at their lowest close in more than 3 years.  For what it's worth, you'd really have to go back to the summer of 2012 to see meaningfully lower rates.

Big banks and big investors have been raising the alarm in various ways (research reports, public statements, CNBC phone calls, etc.) about what might happen to them in the event of Brexit (we're talking about the UK exiting the European Union, by the way).  

The net effect is a massive run on global bond markets and a big, nasty sell-off in equities markets.  US bond markets were still riding the wave from European trading heading into 10am.  There, they found a small extra boost from the worst-ever read on the 5-yr consumer inflation outlook in the Consumer Confidence data.  

But Europe was done buying bonds for the day, and yields moved higher accordingly until Europe was simply done with trading for the day.  After that, Treasuries found their footing and rallied back toward the days stronger levels, but logically chose to remain inside the morning's trading range (typical Friday afternoon following a volatile morning session).