It was not that long ago that the Australian dollar could lay claim to being the best-performing developed market currency in the world against its U.S. rival since the global financial crisis. Amid a spate of interest rate reductions and assorted other negative factors, Aussie’s halcyon days, at least for the moment, appear behind it.

The currency has plunged 9% against the greenback since early May, dragging the CurrencyShares Australian Dollar Trust (NYSEArca: FXA) down 6.4% since May 1. In addition to the Reserve Bank of Australia taking the country’s interest rates to a record low of 2.75%, the Aussie has endured in recent weeks news that legendary financier George Soros shorted the currency. Hedge fund luminary Stanley Druckenmiller followed up with his own bearish commentary on the Aussie. [Currency Diversification With ETFs]

Those gentleman appeared to be onto something because on BlackRock Managing Director Michael Trudel told the Wall Street Journal “there are some pretty prominent hedge fund managers back in the states that have been vocal on getting short the Australian dollar,” James Glynn reported for the Journal.

Prolonged weakness in the Aussie should be good news for at least one ETF: The ProShares UltraShort Australian Dollar (NYSEArca: CROC). Despite its catchy ticker, CROC, has not gotten much attention since its July 2012 debut.

Maybe that is because leveraged ETFs are controversial and the idea has not caught of leveraged currency ETFs is not appealing to all investors. However, CROC deserves this much credit: It is up 12.6% in the past month, meaning it has done a good job of its delivering on its promise to reflect twice the inverse, or -200%, the daily performance of the U.S. dollar against the Aussie. [New Leveraged ETFs Track Australian Dollar]