In commerce, a commodity is a basic good that can be interchanged with other goods of the same type. The normal examples of commodities are gold, oil, beef, grains, and natural gas. Commodities are important to investors and traders as an avenue for diversifying a portfolio beyond securities. Further, commodities tend to move in opposition to stocks. This makes them what many turn to or rely on in periods of market volatility. When traded, they’re typically sorted into four categories: metal, livestock/meat, energy, and agricultural.