Same old story: stocks and oil are setting the tone for bond markets.  This relationship broke down just a tiny bit on Friday afternoon as bonds held their ground despite rising oil prices, but reconnected yesterday as oil and stocks began moving lower.  The correlation has remained extremely high so far this week with all three (stocks, oil, bond yields) hitting bottom at the same time overnight.

Bonds have been under pressure since then, as the risk markets have generally continued the move higher from overnight lows. 

Treasuries and MBS are now trying to hold ground near 'unchanged' levels.  Both are in just slightly weaker territory day-over-day.