The benchmark 10-year Treasury yield plunged to its lowest levels since Nov. 10, when President Donald Trump's election led to a selloff in government paper. Geopolitical concerns strengthened the bid for government paper and other assets perceived as havens, helping to push down the 10-year Treasury yield TMUBMUSD10Y, 0.701% 7.9 basis points to 2.088%. Yields, which move inversely to bond prices, fell across the board in the first U.S. trading session since tensions heated up in North Korea over the weekend. North Korea tested a hydrogen bomb on Sunday, prompting the U.S. to tell the U.N. Security Council that Pyongyang was "begging for war." South Korea also warned that its northern neighbor is preparing to test its intercontinental ballistic missile this week.