In the US there are prime brokers (Morgan Stanley, Goldman etc) who are able to borrow Yen from Japanese banks. Hedge Funds, who must have US$ on deposit with their primer broker, then borrow the yen at the prevailing interest rate which was usually near zero for several decades. The Yen are converted into US$ and invested at the prevailing US$ rate of, say, 3-4%. Thus the Hedge Funds earn the interest rate differential between the Yen and Dollar but assume a risk of adverse currency movement.











