Eclectica founder Hugh Hendry has initiated a substantial short position in Japanese credit, on expectations of a sharp correction in the Chinese growth story.
Japan's central bank is believed to have intervened for the second time in a week to combat the rising yen.
The FTSE 100 opened lower this morning, down 0.31% to 5,529, as miners saw falls across the board.
Multi-managers are boosting their exposure to Japan following the Government's moves to weaken the currency.
The manager of Jupiter's Japan Income fund says Japan's move yesterday to weaken the yen was welcome, but not enough to make investors truly positive on the country.
The FTSE 100 failed to respond to broker upgrades and healthy earnings reports in early trading, advancing only six points, or 0.1%, to 5,562.37 points.
Japan's Government has intervened in the currency for the first time in six years after the yen hit a 15-year high against the US dollar.