That is a 1 year chart of the yield on the 30-year treasury.
In the last two months, the yeild has gone from 2.52% to 3.67%. 2.5% is a shockingly low yield but that surge up is troubling. The Citi technical/strategy folks wrote a note last week predicting the end of the bull market in treasuries and a resulting bear market for the US Dollar, so they probably had something to do with the move. The might be right, though.
The government should have issues 30 yrs all day long at 2.5%