The Yen is by far the weakest major currency in the world, having recently touched an all-time low against the Euro and a four-year low against the USD, despite strong economic fundamentals and a positive current account balance. It has been reported exhaustively that the cause of the Yen weakness are low interest rates, which has spurred investors to borrow cheaply in Yen and invest in higher-yielding currencies. Even domestic Japanese investors are exerting downward pressure on the Yen by shifting funds abroad in the search for yield. The lower the Yen drifts-in complete defiance of economic fundamentals-the greater the risk a sudden reversal poses to global forex markets; at this point, it could be devastating. The Wall Street Journal reports:

The extent of this kind of trading is notoriously difficult to measure. But, according to a Jan. 26 report by Barclays Capital, the magnitude of yen-funded carry trades “is reaching scary levels” not seen since 1998.

Read More: As Yen Slides, Fears Mount Of a Shakeout