As in almost any market, supply and demand have a huge impact on the commodity market. For example, if oil production levels in traditionally rich regions such as the Middle East fall, the prices of these commodities are likely to rise.
Commodity trading is widely regarded as riskier because the market can also be affected by circumstances beyond the control of traders. For example, major political events such as US elections have historically had a significant impact on the prices of precious metals - especially gold - so this is one commodity market that traders will be watching closely as candidates embark on their campaigns.