The dollar and euro made their largest percentage gains against the yen since late 2008 after the Bank of Japan surprised the markets with an ambitious plan to fight deflation in a radical overhaul of policy.
The dollar fell across the board on Wednesday after a report showed the US private sector created fewer jobs than expected last month, raising concerns that recovery has stalled.
The dollar rallied from one-month lows against the yen on Tuesday, benefiting from a rally in U.S. stocks and investor caution ahead of a Bank of Japan meeting this week.
The dollar fell to a nearly four-week low against the yen on Monday as softer-than-expected US manufacturing data suggested the economy may have run out of steam at the end of the first quarter.
The euro hovered near four-month lows against the dollar on Friday, beset by political deadlock in Italy and worries huge losses Cypriot depositors have been forced to stomach.
The euro rebounded from a recent four-month low against the dollar on Thursday, a trend analysts see as tenuous because investors continue to fret about the Cyprus crisis.
The euro fell to a four-month low against the dollar on Wednesday, suffering from growing conviction that Cyprus's rescue will prove a template for future euro zone bailouts.
The euro hovered near a four-month low as mixed messages from European officials kept fears alive that Cyprus' decision to tax large bank depositors would set a bad precedent.
The euro fell against US dollar and Japanese yen Monday as brief enthusiasm brought on by Cyprus' deal with its international lenders swiftly segued into broader fears about the banking sector.
The euro rose against the dollar on Friday, posting its first weekly gain in seven weeks on hopes Cyprus will find a solution before Monday to avert a financial meltdown.
The US dollar rallied after a decision by the Federal Reserve to continue its aggressive monetary easing fueled optimism about the US economic recovery.
The euro dropped to near a four-month low against the US dollar on Tuesday and looked poised to extend losses as uncertainty about Cyprus reignited fears about the euro zone currency.
The euro tumbled to a more than three-month low against the U.S. dollar as a bailout plan for Cyprus that will tax bank deposits spurred contagion worries in the euro zone.
The dollar fell from a seven-month high against a basket of currencies Friday after US data dented optimism about the economy and reinforced expectations the Fed will continue its bond-buying program for the foreseeable future.
The dollar climbed to a seven-month high against a basket of currencies on Wednesday as robust U.S. retail sales data bolstered prospects for the world's largest economy.
The yen rose against the dollar for the first time in a week on Tuesday, rebounding from a 3 1/2-year low, as short and long-term investors opted to book profits.
The dollar rose against the yen Monday, trading near a 3 1/2-year high set the previous session when strong U.S. jobs data spurred speculation the Federal Reserve could back away from its ultra-loose monetary policy.