Federal Reserve Chair Janet Yellen speaks at a news conference following the two-day Federal Open Market Committee meeting in Washington March 18, 2015.

U.S. Treasury yields traded back-and-forth on Wednesday after the Federal Reserve delivered a statement in which it removed all calendar references to raising interest rates.

The FOMC indicated after its March meeting that a rate hike in April was unlikely. The U.S. central bank has kept its key funds rate anchored near zero since late-2008 to spark the economy during the financial crisis.