The yen tumbled past the key psychological level of 150 to the dollar on Thursday for the first time since 1990, despite Japanese policymakers’ repeated threats of intervention to address excessive currency market volatility.The dollar/yen’s break above the key milestone heightens pressure for Tokyo to step into the currency market again to rein in the Japanese currency’s relentless decline. Earlier in the day, Japanese Finance Minister Shunichi Suzuki vowed to take “appropriate steps” against excessive currency market volatility. The Bank of Japan, for its part, ramped up efforts to defend its 0% bond yield cap ... (full story)