Japan might be talking up the yen by saying less about it, the lack of information adding to the sense of uncertainty and putting traders on the back foot.

¡°It seems to me that the government may be changing its approach to FX intervention,¡± said Norihiro Yamaguchi, an economist at Oxford Economics, using market?shorthand?for foreign exchange.

Japan¡¯s currency is now trading near its weakest levels in 40 years against the dollar. For a while, officials issued clear threats. Now, they are saying little or nothing.