The dollar climbed to a more than six-month high against the yen on Monday on speculation the Bank of Japan may expand its already massive economic stimulus.
The euro traded near a five-year peak against the yen and a one-month high against the dollar.
The yen clawed back lost ground against the euro and dollar in Asia on Thursday after touching fresh lows against both, on track for one of its worst monthly performance this year.
The euro rose near a one-month high against the dollar and a four-year high against the yen.
The dollar dropped broadly on Tuesday, as lower U.S. Treasury debt yields drove investors to trim bullish bets.
After going steady for the last few months, the dollar and the yen are about to break up again, according to strategists.
The yen hit a six-month low against the dollar and a four-year trough versus the euro on Monday as a deal on Iran's nuclear program sent risk higher.
The euro climbed to a four-year peak against the yen and rose for a second straight day versus the dollar on Friday.
The dollar jumped to its highest in more than four months against the yen on Thursday.
David Bloom, the global head of foreign exchange strategy at HSBC, lists the currencies that would survive a flight back to the dollar.
The dollar edged lower after Fed Chairman Ben Bernanke said the Fed will maintain its ultra-easy policy for as long as needed.
The dollar edged lower in choppy trading after the Chinese central bank said it would gradually exit from regular intervention in the foreign exchange market.
The safe-haven dollar and yen fell on Monday after China announced its most sweeping economic and social reforms in nearly three decades.
The dollar rose against the euro on Wednesday in a lackluster session with investors continuing to trade on comments from a member of the Federal Reserve that seemed to keep the door open to a first drawdown in stimulus next month.
The dollar eased on Wednesday but still clung near a two-month high against the yen, supported by speculation that the U.S. Federal Reserve is on course to start reducing its stimulus as early as December.
The dollar rose broadly, hitting a one-month peak against the yen on Tuesday on higher U.S. bond yields.
The dollar paused in its advance against the euro on Monday after two days of strong gains.
The dollar soared against the euro and yen after data showing U.S. job growth unexpectedly accelerated in October.
The euro fell to a more than seven-week low against the dollar after the European Central Bank shocked investors by cutting interest rates.
The euro rose as stronger-than-expected German industry data increased uncertainty over whether the ECB would cut interest rates this week.