Invest in currencies. Currencies can be tricky because they usually reflect the strength of the economy that uses them. The only problem with that is that the relationship between the economy as a whole and the factors which influence it — the job market, interest rates, stock market, as well as laws and regulation — aren't often straightforward, and can change very quickly.^[12] Furthermore, investing in a foreign currency is always a bet about one currency relative to another currency, since currencies are exchanged. These components add to the difficulty of investing in foreign currencies.