There are two distinct features to currencies as an asset class:

• You can earn the interest rate differential between two currencies.
• You can profit from changes in the exchange rate.

An investor can profit from the difference between two interest rates in two different economies by buying the currency with the higher interest rate and shorting the currency with the lower interest rate. Prior to the 2008 financial crisis, it was very common to short the Japanese yen (JPY) and buy British pounds (GBP) because the interest rate differential was very large. This strategy is sometimes referred to as a “carry trade.”