The dollar fell to a low against a currency basket on Monday, weighed by concerns about the early days of Donald Trump's administration.
The dollar edged lower in choppy trading on Friday as investors found few reasons to make big bets on the U.S. currency.
The dollar climbed on Thursday as solid U.S. data reinforced a theme of robust U.S. economic growth.
Investors eyed an upcoming speech by the head of the Federal Reserve and U.S. inflation data for clues on the path of interest rates.
Theresa May triggered the pound's biggest jump in eight years.
Sterling was hit by fears that Prime Minister Theresa May will say on Tuesday that Britain will lose its access to the EU single market.
The U.S. dollar gained against the yen and was little changed against the euro on Friday, rebounding from five-week lows.
There is little if any data to support suggestions that traders may have deliberately spurred October's flash crash in sterling, a BIS report said.
The dollar sank to a five-week low below 114 yen on Thursday and was on course for its worst week since November.
Mexico's peso weakened to a historic low of 22 per dollar on Wednesday, shortly after Donald Trump began a news conference in New York.
The dollar edged lower on Tuesday on nervousness ahead of U.S. President-elect Donald Trump's first news conference.
Talk of Britain dramatically reworking trade ties with the European Union after Brexit sent the pound tumbling to two-month lows.
The dollar rose on Friday, boosted by a US jobs report, but was headed for a second straight weekly loss after tumbling the day before.
Some of the biggest gains on record for China's yuan sent currency markets spinning.
Investors were cautious about increasing bets on the greenback before getting fresh clues on the U.S. economy.
Dealers and investors in London returned to push the greenback to within 1 percent of December's long-term highs.
The dollar recovered from a two-week low against a basket of six major currencies.
Weaker-than-expected economic data weighed on the greenback and waning risk appetite boosted Japan's safe-haven currency.
The U.S. dollar hit its highest level in two months against the sterling on Wednesday on concerns over next year's Brexit negotiations.
The dollar inched up against the yen on Wednesday after upbeat U.S. economic data reinforced expectations for economic growth.