The Global X MSCI Greece ETF (GREK), the lone exchange-traded fund (ETF) listed in the U.S. tracking Greek stocks, is up almost 23% year to date. While that sounds impressive, the devil is in the details, as always, for GREK. Over just the past week, GREK has tumbled nearly 6%, bringing its one-month loss to over 7%. During its most recent decline, GREK has slipped below its 20- and 50-day moving averages, although the ETF resides more than 7% above its 200-day moving average. Fits and starts are nothing new for GREK, an ETF that turns six in December.

Greece, now classified as an emerging market by all of the major index providers, is still dealing with the effects of the global financial crisis. From 1999 through 2009, the Greek economy steadily grew, but that growth was fueled by rampant borrowing, which has come back to haunt the country in recent years. (See also: The Origins of Greece's Debt Crisis.)

"Despite an effort in 2010 to rein in spending, the country eventually acknowledged that it was headed towards a possible default," said Global X in a recent research piece. "Given the amount of Greek debt held by major financial institutions around Europe, the ramifications of such a default were massive, even calling into question the Eurozone's survival."

Over the past three years, GREK has lost nearly half its value, while the MSCI Emerging Markets Index is up more than 12%. Greek stocks are also significantly more volatile than broader emerging markets benchmarks. GREK's standard deviation of almost 37% is more than double the comparable metric on the MSCI Emerging Markets Index. (See also: Greek Debt Crisis: What Everyone Should Know.)

In recent years, Greece has enacted dramatic spending reductions, some of which have paid off for the country. "Economically, these measures have amounted to a dramatic fiscal tightening regime in the midst of a recession, a move that has surely stunted the country's ability to recover from recession," according to Globlal X. "Yet at the same time, the country successfully reversed its deficit from an alarming 15% to a modest primary budget surplus in 2016, indicating progress has been made to get its debt levels under control; a necessary condition to eventually return the economy to sustainable growth."

GREK is a de facto bet on the market's view of Greek banks, as the financial services sector accounts for over one-third of the ETF's weight. Energy and consumer discretionary names combine for another 38%. Investors have added $44.1 million to GREK this year, bringing the ETF's assets under management to nearly $385 million. (See also: Political Jitters Put These Europe ETFs in Focus.)