It's All In the Construction With Commodity ETFs | ETF Trends

When it comes to exchange traded funds (ETFs), investment strategy can make all the difference.

Since the year is past the halfway mark, it is fair game to start comparing ETFs within the same sector, and ETFGuide compares three funds which track commodities. The commodities sector has been the one of the most successful for 2008, but the three funds are delivering different results.

iShares S&P GSCI Commodity Indexed Trust (GSG) is up 44.8% and uses a passive method for selecting commodities. GSG weights upon world production, measuring the average production over the past five years.

PowerShares DB Commodity Index (DBC) is up 47.1% and has a different process for selecting and weighting which commodities are tracked on the DB Liquid Commodity Index-Optimum Yield Excess Return Index. DBC is composed of futures contracts on six commodities, with 55% toward energy commodities, using a modified equal-weighting strategy.