Down 8.4% year-to-date, the PowerShares DB U.S. Dollar Index Bullish Fund (NYSEArca: UUP), the tracking exchange traded fund for the U.S. Dollar Index, is one of the worst-performing currency exchange traded funds this year.

UUP tracks the price movement of the U.S. dollar against a basket of currencies, including the euro, Japanese yen, British pound, Canadian dollar, Swedish krona and Swiss franc. Other currencies, including the Australian dollar, yen and Canadian dollar have recently been gaining momentum against the greenback.

Obviously, UUP’s slack year-to-date showing indicates shorting the dollar has been the right way to play the U.S. currency. It may also imply that shorting the dollar has been easy. Moreover, the dollar’s 2017 struggles could be a sign that shorting the greenback is a trade with too many participants.

“Money managers in a Bank of America survey last week labeled it the second-most overcrowded bet across markets, after speculators amassed the biggest net-short position on the dollar in more than four years, CFTC data show,” reports Anna Windemuth for Bloomberg.

Year-to-date, investors have pulled almost $193 million from UUP, a total surpassed by just four other PowerShares ETFs, according to issuer data. However, investors have been tepid toward the PowerShares DB US Dollar Index Bearish Fund (NYSEARCA: UDN). That bearish ETF has seen year-to-date inflows of just $4 million. However, that is about 10% of UDN’s assets under management total. UDN is up almost 9% this year.

Related: Dollar ETF Wobbles, But Isn’t Knocked Out

Although the dollar and UUP have struggled against the backdrop of two interest rate hikes by the Federal Reserve, some currency market observers see potential for the greenback to rally in the second half of 2017. The rising euro has also been a problem for the dollar, but some market observers believe the common currency is set to pullback.

“Meanwhile, comparatively low rates, slowing economic growth and underestimated political risk in Europe will start to weigh on the euro, which has outperformed the dollar this year,” said Sameer Samana, global quantitative and technical strategist at the Wells Fargo Investment Institute, in an interview with Bloomberg.

If UUP closes lower on an annual basis this year, it will be the first time since 2013 the ETF has accomplished that ominous feat.

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