Quote from DrPepper:
I like trading commodities due to the edge sometimes provided by the seasonal tendencies and the COT report. However, the leverage of the commodity market often keeps me out of good trades. Despite their drawbacks, I prefer to trade ETFs that follow a single commodity, such as GLD, SLV, USO or UNG. Even the currencies have ETFs dedicated to a single currency, such as FXA, FXC, FXS, etc. However, there is not a single ETF dedicated to corn or wheat or soybeans or sugar. Something like DBA includes all of these together. The problem is that each commodity has different seasonal tendencies and COT reports, so trading DBA does not help me if I get a set-up with corn. As large as the corn, soybean and wheat markets are, it would seem to me that there would be an ETF dedicated to each one. DBA certainly gets plenty of volume.