The yen leapt on Monday, keeping traders on alert for further intervention to shore up Japan's historically weak currency, days after Tokyo and Washington jointly intervened in the foreign exchange market, Reuters reported. The yen rose 1% in the Asian morning to an intraday high of 156.01 per US dollar, following a more than 3% surge over two sessions last week. Japan's finance ministry confirmed the joint yen-buying intervention on Friday, and Bank of Japan data showed Japan may have bought as much as $58.97 billion worth of yen on Thursday.

BBH's Elias Haddad said history shows joint FX intervention packs a punch and that investors should lean with the official flow, noting all three coordinated US intervention episodes since 1998 were successful, according to Reuters. The yen has been pressured for years by the BOJ's gradual tightening, which has kept yield differentials wide. Goldman Sachs analysts said authorities would likely intervene further if the yen began to unwind the recent move. The yen's strength hammered the dollar, sending the euro to a six-week high of $1.1559, while a fall in oil prices added pressure after U.S. President Donald Trump said he had called off an attack on Iran. Investor focus now turns to Friday's US nonfarm payrolls report for clues on Fed policy.