U.S. sovereign bond prices were lower as investors awaited testimony by Federal Reserve Chair Janet Yellen and tread lightly ahead of Britain's EU referendum set for later this week. Investors also digested fresh supply into the market.
The Treasury Department auctioned $26 billion in two-year notes at a high yield of 0.745 percent on Monday.
The bid-to-cover ratio, an indicator of demand, was 2.72.
Indirect bidders, which include major central banks, were awarded 47.4 percent. Direct bidders, which includes domestic money managers, bought 9.9 percent.
The yield on the 10-year Treasury note, which moves inversely to its price, moved higher to 1.6671 percent, while the yield on the 30-year Treasury bond was up at 2.4718 percent. Two-year note yields also traded higher, at 0.7289 percent.