The yen and the Swiss franc rose while the euro fell after explosions in Brussels spurred inflows into safe-haven currencies and assets.
Hans-Paul Bürkner, chairman of the Boston Consulting Group, suggests what China's president needs to say to reassure the world about China's growth.
Sterling was the biggest mover on Monday, sinking more than half a percent on concerns a split in the ruling Conservative Party over Europe.
The dollar recovered from a five-month low, as traders covered short positions after two straight days of selling.
The yen was volatile on speculation the Bank of Japan was concerned about the Japanese currency's strength.
The Chinese currency has hit a year-to-date high against the dollar, leaving experts contemplating whether officials will step in to devalue the yuan.
I think what you are seeing now is probably the last drive against the dollar, says Boris Schlossberg, BK Asset Management, sharing perspective on the Fed's policy and its impact on global currencies and especially the U.S. dollar.
Chinese banks are creating a web of risk through their wealth management products, raising concerns about the health of the financial system.
The dollar fell sharply against major currencies after the Federal Reserve kept interest rates.
The dollar fell sharply against the yen as weak U.S. retail sales data compounded investors' search for safety.
Currency markets were off to a relatively quiet start on Monday, stabilizing after last week's wild swings.
Analysts at the firm expect the renminbi to weaken to 7 against the greenback by the end of the year.
The dollar was higher, after nearing a one-month low against a basket of major currencies.
As investors digested the ECB's new stimulus package, some are suggesting Draghi has shelved plans to drive the euro lower for the time being.
China's central bank Friday guided the yuan higher against the dollar by the fastest pace this year, leaving some puzzled by the size of the move.
The euro rose to a three week-high against the dollar on Thursday, rallying from a six-week low.
The euro held firm on Wednesday in choppy trading as investors awaited an European Central Bank meeting.
Weak Chinese trade data stoked safe-haven demand for the yen on Tuesday.
The dollar index fell as big gains in oil prices rekindled demand for the euro and commodity-sensitive currencies.
Bill O'Neill, head of U.K. investment office at UBS, discusses if investors should be concerned by any reduction in China's foreign exchange reserves.