as far as I am concerned this fund behaved just as it should. There was a massive sell off in the spring, even of quality short term paper, investors came back to their senses and, 8% gain ! Absent another panic the fund should go up when rates go down and go down when rates go up. Interestingly the spread between treasuries and corporate would imply there is still money to be made, in addition to yield, in investment grade. Long term though it has paid to stick with the treasuries since you have not historically been compensated for risk with investment grade. The caveat of course is the US governments historic borrowing with no way to pay except to raise taxes. Treasuries are no longer the sure bet long term they once were.