The dollar started the week pinned near two-week lows on Monday as traders questioned whether the recovery from the pandemic in the United States would be as fast as expected.
Bitcoin traded below $49,000 after pushing to a record $49,714.66 over the weekend, following endorsements last week by Tesla and BNY Mellon.
The dollar index was at 90.427, close to last week's low of 90.249 - a level not seen since Jan. 27.
The gauge hit a two-month top of 91.6 on February 5 on hopes that a US rebound would outpace other major economies, but has since retreated amid disappointing employment data.
"The rebound in the dollar ... was initiated by relative US economic outperformance, or expectations thereof," said Shinichiro Kadota, senior currency strategist at Barclays Capital in Tokyo. "Now the market is looking for actual evidence that the US economy is outperforming."
"The economic data needs to improve," he said.
The euro was little changed at $1.21215 after climbing 0.6% last week.
The dollar rose 0.2% to 105.09 yen, recovering from some of the previous week's 0.4% loss.
Many financial markets in Asia remained closed on Monday for Lunar New Year, with the United States also out for Presidents Day.
There has been a tug-of-war over the dollar's direction this year with some market participants expecting it to strengthen as the US economy outperforms peers including Europe.
Others view the US recovery as a key driver in a global reflation narrative that should lift riskier assets at the dollar's expense.
"The US outperformance story ... has a lot further to run thanks to fiscal stimulus and faster vaccine deployment," Westpac strategists wrote in a client note.
"But ongoing aggressive US reflationary fiscal and monetary policy settings will leave DXY on a sustained medium-term bear trend," the note said, referring to the dollar index.
Bitcoin last traded at $48,772, little changed from the record high. It surged roughly 25% last week for its best performance since the turn of the year.