The U.S. dollar's declines are likely to continue because a vaccine and the expected choice of former Federal Reserve Chair Janet Yellen as U.S. President-elect Joe Biden's next Treasury secretary relieve two big uncertainties for investors.
"Rising yields may lend the dollar some support, but the overall direction is it will head lower," said Junichi Ishikawa, senior foreign exchange strategist at IG Securities in Tokyo.
"The trend has shifted to favour risk assets. Yellen will team up with the Fed and support the economy. U.S. rates will remain low for a long time."
The dollar stood at $1.1903 against the euro on Wednesday in Asia, close to a two-week low.
The British pound bought $1.3359, close to its highest in more than two months.
Against the yen, the dollar held steady at 104.54.
Research suggesting that a COVID-19 vaccine could be available before year end has sent U.S. stocks surging to record highs and reduced the appeal of holding the dollar as a safe-harbour currency.
Risk appetite has also improved after the outgoing U.S. President Donald Trump's administration began cooperating with the Biden transition, and after reports that Yellen, an advocate of more fiscal spending, will take the top job at Treasury.
The dollar index, pitting the dollar against a basket of six major currencies, was at 92.109 after falling 0.4% on Tuesday.
The onshore yuan rose to 6.5818 per dollar on hopes for better Sino-U.S. ties under Biden. Other Asian currencies also edged higher.
The Antipodean currencies were already on the front foot as investors unwound bets for additional monetary easing in both countries.
Improving risk appetite means the Australian dollar's next target is its high of $0.7413 on Sept. 1.
The New Zealand dollar, which has rallied 5.6% so far this month, is trading just shy of its strongest since June 2018.
Bitcoin, the most popular cryptocurrency, eased slightly to $19,046 but was still close to its record of $19,666 from December 2017.
(Reporting by Stanley White; Editing by Christopher Cushing) ((email@example.com; +81 (0)3 4563 2799; twitter.com/stanleywhite1 ;))