Unless you've been hiding in a cave for the past several years, you know just how hard the U.S. dollar's value has been hit. Yet despite ongoing concerns about weakness in the economy, the dollar has reversed its seven-year slide in recent months, rising nearly 10% against the euro.

It's hard to say whether this reversal of fortune will last. But an exchange-traded fund that focuses on a strong greenback, the Powershares U.S. Dollar Bullish Fund (AMEX:UUP), offers investors an opportunity to benefit if the dollar keeps rising.

Fund facts

  • Inception date: Feb. 20, 2007.
  • Expense ratio: 0.50%.
  • Net assets: $736 million.

Fund specifics
The Dollar Bullish fund tracks Deutsche Bank's (NYSE:DB) Long U.S. Dollar Futures index. The index is made up of futures contracts that will go up in value if the dollar strengthens against the euro, Japanese yen, British pound, Canadian dollar, Swedish krona, and Swiss franc.

Portfolio fit?
Slowing economic growth in all corners of the globe has investors questioning whether global markets can successfully decouple themselves from the U.S. economy. Instead of feeling comfortable about their foreign investments, as they have for the past several years, many investors are concerned that investing abroad may not give them the safety and security associated with stocks in the world's largest market.

For years, the dollar has been in a death spiral. But recently, investors seem to have realized that the U.S. is unlikely to be the only economy to suffer a slowdown. That's how, despite U.S. weakness, it's entirely possible that the dollar may regain favor for a long while.

On the other hand, the U.S. does have its own particular problems. For those who don't buy into the strong dollar argument, there are nearly 30 other currency ETFs, many of which will benefit if the dollar starts falling again. Whether it's WisdomTree Dreyfus Chinese Yuan (NYSE:CYB) or  CurrencyShares Euro Trust (NYSE:FXE), you can make bets on specific currencies. Or you could invest in the Powershares U.S. Dollar Bearish Fund (AMEX:UDN), which has the opposite characteristics of the Dollar Bullish Fund.

Whichever fund suits your view of the future, be aware that the currency markets can maintain trends for significant periods of time, but can change direction suddenly and display considerable volatility. In addition to market movements, currency ETFs are influenced by the political climate, economic conditions of their specific countries or regions, and interest rates. In general, currency ETFs aren't a must-have investment for your portfolio. But if you're convinced that the dollar is headed up after a long malaise, the Dollar Bullish ETF is one way to put your money where your mouth is.

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Fool contributor Zoe Van Schyndel lives in the Seattle area, where she enjoys the coffee and natural wonders. She does not own any of the funds or securities mentioned in this article. The Motley Fool has a disclosure policy.