U.S. President Donald Trump said on Tuesday that the first phase of an American trade deal with China would be signed on Jan. 15 at the White House. The dollar index (DXY) was down 0.36% to 96.388, its fourth consecutive session in the red and its weakest level since July 1. The Phase 1 trade agreement, which was reached earlier in December, has reduced demand for the safe-haven currency, pulling the dollar down 1.92% in the last month. December's move has undone much of the dollar's strong 2019 thanks to the relative outperformance of the U.S. economy and a long period of uncertainty in the negotiations between Washington and Beijing. On the last trading day of the year, the dollar was up just 0.25% for 2019 compared to 4.4% in 2018. At the end of November, it was up 2.18% for the year. The shift also reflects investor bets that the dollar will weaken further in 2020.