The Bloomberg Dollar Index fell to its lowest level since mid-May, posting its biggest drop in three weeks, after bonds rebounded on the U.S. Treasury's surprise decision to increase long-dated Treasury buybacks. According to Sina Finance, the index briefly fell 0.7%.

The dollar weakened against all major currencies, including the yen, while the Swiss franc and Swedish krona led gains. U.S. long-dated Treasuries rebounded, and the 30-year yield fell about 8 basis points after earlier rising to its highest level since 2007.