USD/JPY, Interventions and 155U.S. DOLLAR / JAPANESE YENFX_IDC:USDJPYCityIndexIt’s no surprise that USD/JPY has stalled at 155. Japanese officials have previously warned that sustained moves above this level could prompt currency intervention. Today I look at how the yen has behaved around 155 in the past, and what that could imply for volatility from here. Matt Simpson, Market Analyst at City Index.