Yields on benchmark 10-year debt—used to calculate mortgage rates and other consumer loans—closed 2014 at 2.173 percent versus 3.03 percent at end of 2013, making it the biggest annual decline in the yield since 2011.
U.S. Treasury prices gained momentum on earlier this week as stocks weakened and investors kept a cautious tone due to uncertainty over Greece's future in the euro zone.
The left-wing Syriza party, which opposes Greece's EU/IMF bailout and is leading in opinion polls ahead of an election next month, has said it wants to abandon many of the drastic spending cuts that are central to the nation's economic rehabilitation program.
That uncertainty has helped U.S. bonds rally strongly this week, though thin liquidity before the New Year's holiday has exacerbated price moves.
Bonds were also lifted on Wednesday after jobless claims came in a bit higher than expected.
This story has been updated to reflect the proper levels for the US 10-year bond and the correct times for later economic indicators.