Troubles in Greece have only incited the popularity of exchange-traded commodities in the wake of what could be the largest bankruptcy since the credit crunch began.

Often suffering from limited liquidity, currency funds are now on the up and up. The CurrencyShares Euro Trust (FXE: Quote, Profile, Advanced Chart, News), which has an average volume just under 580,000 shares daily, posted volume of over three million shares on February 19, the day Greece’s debt issues came to light. Since that time, the volume has increased over 60%, reaching nearly one million shares daily.

Although overall volume for the 30 different currency ETFs on the market remains thin, a growing number of ETF investors are using exchange-traded currencies as a way to hedge their portfolios. The sector recorded $7 billion in assets under management in February, MarketWatch reports.

Often seen as a leading indicator of overall commerce and business spending, airline ETFs are leading the overall stock markets. The Claymore Airline ETF (FAA: Quote, Profile, Advanced Chart, News) has posted gains of 73% since last summer.

After the entire sector nearly plunged into bankruptcy after 9/11 and fought off higher oil prices in 2007-2008, the sector looks stronger as balance sheets improve industry wide. The industry is driven almost entirely by business travelers and vacationers, two groups that are the most affected during a recession.

The sector isn’t facing perfectly clear skies, however, as analysts suspect the low oil prices enjoyed this winter will head higher during the summer, again pinching airline’s profit margins, MarketWatch reports. At least for now, the flight plan appears unrestricted. The following chart illustrates the growth for FAA over the past year.

While some analysts are calling gold a bubble, others are forecasting where the precious metal will peak. For the first time in nearly two decades, the once boring metal has brought out the best and brightest market forecasters to put their money where their mouth is.

A Bloomberg survey of 22 analysts reveals that 15 are forecasting a run to $1300 an ounce in 2010, which 17% higher than where the yellow metal rests today, BusinessWeek reports. Much like the oil explosion throughout 2008, analysts are taking shots at gold’s peak price. When this happens, investors generally feel the bull run is over, with the bulk of the demand already removed from the market at lower price points.

While gold cools, another precious metal is just heating up. ETFSecurities Platinum ETF (PPLT: Quote, Profile, Advanced Chart, News) has accepted $440 million in assets as investors look for growth opportunities in the automotive sector, which represents the biggest driver of growth for both platinum and palladium, the Wall Street Journal Reports.

Option volume in the Market Vectors Russia (RSX: Quote, Profile, Advanced Chart, News) indicates that Russian markets may soon enter a bear market. Uncharacteristic put volume reflects a dip of greater than 17% by May.

Open interest on the popular ETF rose to 60,608 put contracts, 2.42 times as many call contracts, which suggest a dip is in order. Of all the contracts, the $25 May puts were the most active, signaling that investors are looking for a 17% decline in Russian stocks by May expiration, which is just three months away, BusinessWeek reports. Nearly a fifth of all option action in the Market Vector’s fund is in the May $25 put.

Already Russia’s Micex Index has fallen some 8.3% since January highs, and analysts suspect the index will continue to decline as Russia’s top export, oil, remains inexpensive.

Although 2010 continues show the promise of a recovery, what was hot in 2009 is appearing to cool as 2009’s losers become 2010’s big winners.

In 2009, gold had the Midas touch, but as the commodity markets cool from ebbing inflation fears, an unlikely candidate is leading the charge in the best performer category. Only 46 days into the new year, the U.S. Home Construction Index Fund (ITB: Quote, Profile, Advanced Chart, News) has posted the best unleveraged return year-to-date of 8.7%, according to MarketWatch. Improving housing starts, consumer confidence and subsidies for home purchases have fueled the ETF’s growth.

Investors look to the home construction industry to time peaks in home prices. Homebuilders peaked in 2005, well before residential prices, reflecting on the changing tide of the industry as a whole. The following chart illustrates ITB’s performance over the past year.