Treasury prices were all over the map after the Federal Reserve announced it was extending a program to buy bonds with long maturities.
The price of the benchmark 10-year Treasury note on Wednesday fell 75 cents for every $100 invested. The yield, which is used as a benchmark for mortgages and corporate loans, rose to 1.63 percent from 1.62 percent late Tuesday.
However, the price of the longer-term 30-year bond rose 59 cents and its yield fell to 2.71 percent, from 2.73 percent Tuesday.
The Fed said it will continue to buy bonds that mature in six to 30 years to help keep long-term interest rates low. By doing that, the Fed hopes to spur Americans to use low interest credit to buy more cars and homes.
The central bank said its action was in response to slower growth in household spending, "elevated" unemployment, and the depressed housing market. The central bank also noted that Europe's debt crisis threatens the economy.
The yield on the two-year note rose to 0.31 percent, from 0.29 percent.
In the market for short-term Treasury bills, the three-month T-bill paid a yield of 0.08 percent, down from 0.09 percent.