Ten-year note yields reached the lowest level in a week as crude oil traded near the least in five years and risk appetite ebbed. The security's yield advantage over Group of Seven peers was almost at an eight-year high after Greek Prime Minister Antonis Samaras failed yesterday to win backing for his presidential nominee, a development that risks severing the nation's bailout accord. The yield curve, the gap between two- and 30-year yields, was at almost a six-year low.

"The safe-haven bid has been a major theme in the fourth quarter," said Adrian Miller, director of fixed-income strategies at GMP Securities in New York. "That will continue to play out as one of the catalysts that will keep the long end relatively well anchored as the front end lifts due to Fed tightening."