NEW YORK ( TheStreet) -- Last Friday, the Japanese yen completed its best weekly performance since June, hitting levels of more than 96 against the dollar.These moves were relatively surprising, given the lack of currency volatility that is usually seen during the summer months. But this strength in the yen should be viewed as a selling opportunity, as second-quarter GDP growth in Japan is suggestive of a major reversal that will likely generate a period of prolonged weakness in the currency. This week's data show the Japanese economy grew at a slower rate of 2.6% (on a yearly basis), as reductions in business investment undermined increases in government spending designed to end decades of well-publicized deflation. These results are significantly less than the 3.8% rate posted in the first quarter and the market's consensus estimates of 3.6%. Additionally, July's industrial production figures fell by 3.1% when compared to the prior month. In all, these numbers will lead to more vocal arguments that the Bank of Japan's aggressive quantitative easing programs (the so-called policies of Abenomics) have been largely ineffective, and that additional stimulus injections will be needed as a means to support the country's struggling economy. This is a clear negative for the Japanese yen, as any further central bank easing will be directed at weakening the currency in support of export companies. Investors with active exposure in the CurrencyShares Japanese Yen Trust ETF ( FXY) should be looking to sell in favor of instruments that track the greenback, such as the PowerShares DB US Dollar Index Bullish ETF ( UUP).