Because FORX is actively managed, fund holders will need to check the holdings regularly to stay informed about any major strategy changes. The other fund is the CurrencyShares Singapore Dollar Trust ( FXSG) which is issued by Guggenheim which bought Rydex in September, 2011. Singapore is considered a stable currency and serves as something of a benchmark in its region. Singapore has several appealing attributes including an unemployment rate below 2% and a current account surplus. There are also some less appealing data points including an inflation rate above 4% and a debt to GDP ratio of 100%. CurrencyShares generally pay dividends based on overnight cash rates of the respective country but interest rates in Singapore are very low. Singaporean two-year sovereign debt only yields 0.27% and the fund has a 0.40% expense ratio. Investing in currencies is different than investing in equities or fixed income. Currencies trade relative to other currencies and the trends can be counterintuitive. Where investors have foreign exposure to stocks and bonds for diversification purposes so too can it make sense to diversify cash in a portfolio into foreign exposure but the learning curve should be steep before considering these funds. At the time of publication, the author held no positions in any of the currencies mentioned.Follow Roger Nusbaum @randomrogerThis article is commentary by an independent contributor, separate from TheStreet's regular news coverage.