Commodities are more volatile than most assets. The supply-demand dynamics of commodities are continuously changing, and sometimes very rapidly.
Different commodities will have different levels of volatility, of course. Some commodities are extremely volatile. For example, natural gas has had a volatility of almost 45% in some periods, and gold has experienced movements of 20-30% per year lately.
Crude oil prices fell some 50% in 2015, as a global supply glut was met with weakening demand, particularly from China. Gold is actually on the less-volatile side of the spectrum for commodities. Silver, Nickel, and crude oil tend to be on the upper end of the spectrum along with exotic metals such as platinum and palladium.
Some of the most volatile derivative contracts, though, are those written on oil, rice, wheat, and corn. Between hard and soft commodities, soft commodities may be more volatile due to their shorter shelf-life.
If you decide to invest in any type of commodity, expect plenty of volatility along the way.