Agree with what the others are saying.... Bond prices might continue to weaken for a few more weeks, but remember that Sept. and Oct. are often poor for stocks, and good for bond prices. So I'm thinking that BOND will recover all its losses and then make some gains by the end of October.
Interest rates are rising to a small degree, with 10 year treasury going from 1.45% up to 1.90%, meaning face value of bond holdings are declining somewhat as they move down. Positive econ data and less tension over Europe have caused rates to rise. General wisdom on CNBC World is that this will reverse soon.
Also, just like the other guy, I purchased additional shares yesterday.