Commodity exchange-traded funds (ETCs), which debuted in 2004, enable investors to access an asset class previously difficult or expensive to access. Although a small segment of the overall exchange-traded fund (ETF) universe, ETCs have grown in popularity with both speculators and investors looking for long-term portfolio diversification. Examples of the types of commodities that are now accessible through ETCs include gold, oil, and agricultural. The literature on ETCs is limited, but academic and industry work has centered on using futures contracts to replicate the performance of the underlying commodities spot price as well as the effect additional capital has had on the integrity of the futures market. This chapter covers this topic by reviewing the growth, investment strategies, and regulatory structure of ETCs as well as the underlying effects these funds have had on the underlying markets with which they engage.