The dollar has enjoyed a comeback as market concerns over European debt has weakened the Euro.

UUP

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The PowerShares DB US Dollar Bullish Fund (UUP) is up nearly 6% over the past three weeks while the Market Vectors Double Short Euro ETN (DRR) is up 15% over the same period.

The Euro began to decline against the dollar earlier this month as the Ireland debt crisis reemerged forcing an EU bailout.  Concerns over similar problems in Spain and Portugal have investors continuing to flee the Euro in favor of the dollar.

UUP tracks the DB Long US Dollar Futures Index by investing in futures contracts.  The fund’s expense ratio is 0.75%.

DRR tracks the performance of the Double Short Euro Index. As the Index is two-times leveraged, for every 1% weakening of the euro relative to the U.S. dollar, the level of the Index will generally increase by 2%, while for every 1% strengthening of the euro relative to the U.S. dollar, the Index will generally decrease by 2%.

Market Vectors Currency Exchange-Traded Notes are senior, unsecured debt securities issued by Morgan Stanley that deliver exposure to the exchange rate of foreign currencies. The ETN’s annual investor fee is 0.65%.

For other ETF investing options, see the list of currency ETFs.