There is a decent chance that most folks would not guess that a currency ETF tracking a risky emerging markets currency pulled in $500 million in assets last week, but that is exactly what the WisdomTree Brazilian Real Fund (NYSEArca: BZF) did.

Sudden appetite for BZF could be tied to a small amount of money managers adding the ETF to portfolios as part of quarterly rebalancing. Then again, the real has recently been a strong performer and previously has not been nearly as weak as other emerging markets currencies such as the Indonesian rupiah. [Brazil ETFs Languish]

BZF is up 6% in the past month and is only down 1.7% year-to-date, a solid performance compared to the woes of the rupiah and Indian rupee. The real is trading slightly lower today against the dollar, but that could be a case of some profit-taking in the Brazilian currency after it touched a four-month high last week.

Over the weekend, central bank President Alexandre Tombini said that Brazil may extend into 2014 the $60 billion program of foreign-exchange swaps and credit lines to support the currency and curb inflation as the U.S. tapers its monetary easing efforts, Bloomberg reported.