Treasurys rallied Tuesday as investors rushed into safe assets to avoid turmoil on global stock markets.
The Dow Jones industrial average fell 203 points, its worst loss this year. Stocks also fell more than 3 percent in Germany, Spain and France.
The main worry was that not enough private investors such as hedge funds would agree to swap out their Greek government bonds for new ones with lower values. The swap is vital for Greece to reduce its debt and get more bailout money from international lenders. Without the help, the country could default.
The 10-year Treasury note rose 56.2 cents for every $100 invested. Its yield fell to 1.95 percent from 2.01 percent late Monday.
The 30-year bond rose $1.46, sending its yield down to 3.08 percent from 3.15 percent.
The yield on the two-year Treasury note fell to 0.28 percent from 0.30 percent late Monday. The three-month Treasury bill paid a yield of 0.07 percent, up from 0.06 percent.