The Japanese yen recently hit 150 against the US dollar, the market psychological threshold, which also marks the weakest level not seen since August 1990. That was the level that market investor thought could prompt Bank of Japan (BoJ) to intervene to prop up the currency, to be accompanied by its exit of super easy monetary policy.
Surprises are fine in central banking provided they don’t land too frequently – and are of the right kind, preferably dovish. The tricky part about the Bank of Japan (BoJ) is that the bombshells come often and have not been of the favourable variety.