Prices of 10-year government bonds plunged Thursday, driving the yield on the key issue to a nine-month closing high following weak demand at an auction for new 10-year bonds earlier in the day.
In interdealer trading, the yield on the No. 250 10-year, 0.5 percent government bond issue surged 0.225 percentage point from Wednesday to 1.125 percent, its highest closing level since last Oct. 10.
The surge in yields is bad news for the nation's borrowing costs.