Today was one of those unofficial 3-day weekend type of Mondays with light volume, light trader participation, and "drifty" trading momentum.  A market holiday in Tokyo (Asian market hours' requisite hub for cash Treasury trading) didn't help start the day off strong for the US bond market.  but even after the European session began, volumes remained well shy of recent averages.  

The onset of domestic trading saw progressively more activity but it was really only the 9:30am NYSE open that brought any appearance of conviction.  Even then, it wasn't much conviction (just over 1bp of improvement for 10yr yields).  

We tend to see opening/closing bells garner the biggest moves of the day when traders are tuned out amid an absence of meaningful data, participation and volume.  With this being peak vacation season, the deficit of participation at trade desks will remain a factor.  But tomorrow brings quite a bit more data than today, including the important Retail Sales numbers.  Even with thinner staffing, there's a better chance of a logical response (weaker sales = stronger bonds and vice versa).