The yen jumped more than two percent to 20-month highs against the dollar on Thursday after the Bank of Japan kept monetary policy steady ahead of a U.K. referendum on European Union membership next week that could roil markets.
USD/JPY tumbled 2.13% to 103.75, the lowest level since August 2014 after the BoJ left monetary policy on hold at the conclusion of its two-day meeting on Thursday.
BOJ officials voted to continue expanding the monetary base at an annual rate of about ¥80 billion.
The BoJ also flagged the EU referendum on June 23 as a key geopolitical threat to the Japanese economy, along with the “European debt problem”.
The decision came after the Federal Reserve also cited the referendum as a factor in its decision on Wednesday to keep interest rates on hold.
The dollar had already weakened against the other major currencies after the Fed kept rates unchanged and lowered forecast for how much they expect to hike interest rates in the next few years.
The U.S. dollar index, which measures the greenback’s strength against a trade-weighted basket of six major currencies, was down 0.23% at 94.45.
The dollar was little changed against the euro, with EUR/USD at 1.1263.
The single currency was sharply lower against stronger yen, with EUR/JPY down 1.99% at 116.99, the weakest level since January 2013.
The pound was also lower ahead of the Bank of England’s latest interest rate announcement later on Thursday.
No changes to monetary policy are expected but the meeting minutes could contain a fresh warning about the risks posed by next week’s referendum.
GBP/USD was down 0.36% at 1.4153, while EUR/GBP was up 0.44% at 0.7960.
Sterling tumbled more than two percent against the yen, with GBP/JPY dropping 2.35% to 147.09, the lowest level since April 2013.