The ICE Futures' dollar index .DXY, a measure of the greenback's value against a basket of six major currencies, fell 0.6 percent to 79.649.
Benchmark 10-year Treasury notes US10YT=RR declined 2/32 lower in price to yield 3.55 percent.
The front end of the Treasury curve traded higher after comments late on Tuesday from San Francisco Fed Bank President Janet Yellen who said the fed funds rate could stay pat for "the next couple of years."
The two-year note US2YT=RR traded 4/32 higher in price to yield 1.05 percent.
U.S. crude settled 58 cents lower at $69.31 a barrel, after rising as high as $71.85. London Brent crude fell 51 cents to settle at $68.79 a barrel.
Gold climbed as the China news about a reserve currency sent the dollar reeling, highlighting the status of gold as a hedge against a falling U.S. currency.
U.S. August futures GCQ9 settled up $13.90 at $941.30 an ounce in New York.
Asian stock markets were mixed. The broad MSCI index of Asia-Pacific shares excluding Japan .MIAPJ0000PUS edged down 0.2 percent. Tokyo's Nikkei share average .N225 fluctuated heavily before closing 0.2 percent lower.