These are some of the reasons why there is price fluctuations in different commodities : 1. Demand and supply of different commodities are different with time. When demand is high of a commodity its prices rises and vice versa.This is basically in case of agricultural commodities as its prices are most affected by the change it demand and supply pattern. 2. In case of base metals and precious metals changes in monetary policy, GDP these factors affects its price. Also demand and supply pattern is responsible to certain extent.As during festive season in country like India demand for precious metals rises to large extent. 3. Prices of base metals are affected mostly because of industrial and manufacturing related developments across the globe.