U.S. policy tightening has always been a concern for the emerging market bloc. As we already know, taper talks roiled the emerging markets in 2013 and then kept on upsetting the league occasionally as and when rate hike fears emerged. The year 2018 hasn’t been spared as well.As talks of faster-than-expected Fed rate hikes started doing rounds, U.S. Treasury yields moved higher and the greenback gained strength. U.S. 10-Year Treasury bond yields are hovering around 2.90% currently, up from 2.46% at the start of 2018.As a result,Invesco DB US Dollar Bullish UUP has added 5.3% in the year-to-date frame (as of Sep 5, 2018) and weighed on emerging economies that run current account deficit (CAD). Plus, U.S.-Sino trade tensions are added concerns.Added to the woes, crisis deepened from August with the freefall of Turkish lira (down 25% in August against the greenback) due to a diplomatic tussle with the United States as well as deteriorating economic conditions (read: Turkey Issue Hurt EMs in August: 5 Least-Hurt ETFs).Argentina has also been posing threats to EM stability amid concerns that president Mauricio Macri's policy to cut government spending and avoid a recession will likely trigger social conflict that could oust him from presidency. Argentina's peso plunged 29% against the U.S. dollar in August (read: Top ETF Stories of August). The Indonesian rupiah dropped to its weakest level since the 1997 Asian financial crisis, while India's currency slipped to an all-time low. WisdomTree Emerging Currency Strategy ETF CEW is off 9.4% this year (as of Sep 5, 2018) (read: Inverse EM ETFs to Gain as Currency Turmoil Deepens).The contagion of the Turkey-Argentina issue and the impact of the dollar rally have proved to be severe for the EM bloc lately. Among the bloc, the vulnerability appears extreme for the ‘Fragile Five’ countries — Brazil, Turkey, India, Indonesia and South Africa.Let’s take a look at the fundamentals of each country and see if each pillar of the fragile bloc is uniformly weak.iShares MSCI Turkey ETF TURTurkey's GDP grew 2% sequentially in Q1 following a 1.7% expansion in the previous period. But the economy is in an acute currency crisis. The country had a CAD of 5.50% of GDP in 2017. Higher oil prices are adding to the woes as the country imports more than 90% of its oil requirement. The country’s inflation was about 18% in August — the highest since 2003. As a result, the economy is in stagflation. The lira has plummeted 76% against the dollar since January 2018. TUR is down 54.9% this year (as of Sep 5, 2018). The fund has a Zacks ETF Rank #5 (Strong Sell).iShares MSCI South Africa ETF EZASouth Africa slipped into recession in the second quarter for the first time since 2009 due to president Cyril Ramaphosa’s efforts to jumpstart the economy after a decade of stagnation. The South African economy shrank 0.7% quarter-on-quarter in Q2 against analysts’ expectations of 0.6% expansion. In the past three months, the rand has lost 15% against the U.S. dollar. With the country’s mining sector — one of the key contributors to GDP — in the tight spot, the fund may lose more. The fund, down about 28.5% this year, has a Zacks ETF Rank #4 (Sell).iShares MSCI Indonesia ETF EIDOThe country has banked on back-to-back rate hikes lately to contain the slump in its currency. This is likely to hinder growth. Indonesia’s CAD was 1.70% of its GDP in 2017. Its GDP grew 4.21% sequentially in Q2, beating market consensus of 4.08% expansion. Notably, growth was the strongest since 2005. The fund has a Zacks ETF Rank #3 (Hold) but it has lost 25.1% this year (read: Indonesia Banks on Back-to-Back Rate Hikes: ETFs in Focus).iShares MSCI Brazil ETF EWZBrazil's economy recorded much slower growth in the second quarter due to a trucker strike and electoral uncertainty. However, Brazil’s CAD was much lower at 0.48% of GDP in 2017. The fund, which is down 25.2% this year, has a Zacks ETF Rank #4 (read: ETF Asset Report of August).iShares India 50 ETF INDYThis one appears to be the strongest withGDP growing 8.2% in the first quarter of fiscal 2019, marking the strongest growth since first-quarter 2016. India has been able to reduce its current account deficit to 1.9% of GDP in the 2017-2018 fiscal year from 5% in 2013. BlackRock sees a buying case in India, courtesy of “limited contagion” to EM shocks. The fund has a Zacks ETF Rank #3 and has lost the least (down 2.3%) this year in this so-called fragile group.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ISHARS-BRAZIL (EWZ): ETF Research Reports ISHARS-S AFRICA (EZA): ETF Research Reports PWRSH-DB US$ BU (UUP): ETF Research Reports ISHARS-SP INDIA (INDY): ETF Research Reports WISDMTR-EMG CUR (CEW): ETF Research Reports ISHARS-MS INDON (EIDO): ETF Research Reports ISHRS-MSCI TURK (TUR): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report