Greece may be on the verge of exiting the eurozone, but investors appear to be “bottom fishing” as they plunged into the Global X FTSE Greece 20 (NYSEArca: GREK) in the past week, sending its price up almost 20 percent -- even before the outcome of parliamentary elections there scheduled for Sunday, June 17.

GREK was the best-performing U.S.-listed ETF in the past week ended Thursday, June 14, adding 19.15 percent, according to data compiled by IndexUniverse.

The U.S. stock market continued to rally throughout the week, as investors started positioning themselves for possible Federal Reserve action in response to uncertainty in the eurozone. The Dow Jones industrial average closed at 12,651.91 yesterday, increasing nearly 1.9 percent from its June 7 close of 12,416.83, according to data posted on the Yahoo Finance website.

Energy funds also gained ground – especially natural gas ETFs, which are benefiting from views that oil prices are sure to rise should the Fed launch its third round of bond buying. Such quantitative easing is aimed at keeping borrowing rates low to encourage job-creating economic activity.

The U.S. central bank has launched two such programs since the market first collapsed in September 2008 – hence the term “QE3,” which is market-speak for the third time the Fed will have resorted to such extraordinary measures since the financial crisis began.

Worst Weekly Performers

The PowerShares S&P Emerging Markets High Beta Portfolio (NYSEArca: EEHB) was the worst performing ETP of last week, shedding 9.83 percent over the last week. The high beta fund exposes investors more acutely to the vagaries of developing world equities.

Some single-country ETFs were affected by the state of the eurozone as well, including the Market Vectors Indonesia Small Cap (NYSEArca: IDJX) and the Global X FTSE Argentina 20 (NYSEArca: ARGT) which dropped 5.75 percent and fell 4.17 percent, respectively.

A number of VIX-related ETNs performed poorly last week, the worst was the ETRACS 1-Month S&P 500 VIX Futures ETN (NYSEArca: VXAA) which declined 8.89 percent.

Top 10 Weekly Performers, Excluding Leverage/Inverse Funds and <1,000 Shares Traded

Disclaimer: All data as of 6 a.m. Eastern time the date the article is published. Data is believed to be accurate; however, transient market data is often subject to subsequent revision and correction by the exchanges.