Hedge fund manager Kyle Bass said that unconventional policies and negative rates aren't working for the Bank of Japan.
The yen jumped to a 18-month high against the dollar, extending gains that have undermined Japanese officials' attempts to reflate Japan's economy.
As the U.S. dollar fell to its lowest since January 2015, currency experts told CNBC the currency's decline had further to run.
The Bank of Japan made a “fateful miscalculation” when it opted to hold interest rates at its meeting last week, Goldman Sachs has said.
The dollar recovered slightly on Monday from its biggest weekly fall in more than seven years against the yen.
China's manufacturing activity expanded in April, but only marginally, official data showed Sunday, raising doubts about the pickup's sustainability.
The yen built further on a round of strong gains since the Bank of Japan meeting, moving to an 18-month high against the dollar.
The PBOC guided the yuan higher at the sharpest pace since 2005 on Friday in a move attributed to the dollar's weakness against major currencies.
The dollar pared losses against the yen, but was still on track to notch its biggest daily loss against the Japanese currency in eight months.
Frank Lavin, chairman and CEO of Export Now, says FX volatility is more likely to affect commodity producers but not retailers with secular demand.
The dollar index briefly popped, holding about 0.2 percent higher, before holding slightly lower.
The dollar weakened against major currencies after weaker-than-expected U.S. economic data reinforced views that the Fed would take a dovish stance.
The U.S. dollar slipped against the yen on Monday as traders took profits from the greenback's recent rally against the Japanese currency.
The yen hit a 2 1/2-week low against the dollar on a report said the Bank of Japan was considering helping banks by applying negative rates.
The dollar recovered against the euro after ECB meeting as traders focus on next week's Fed meeting.
Commodity-linked currencies such as the Australian and Canadian dollars inched towards recent peaks on Wednesday.
Commodity currencies like the Australian and New Zealand dollars soared to 10-month highs against the U.S. dollar.
The country wants to boost pricing power and expand its influence in the global bullion market.
Commodity currencies slipped while the safe-haven yen gained ground after major crude exporters failed to agree on an output freeze.
A China official praised Yellen's clear communication and cautious approach, adding the mainland hopes Fed policy will boost its own economy.