The Price of Cocoa in Ghana and Kukdivar

The price of cocoa as a commodity is more volatile than other agricultural commodities like wheat or corn. And yet the price on the supermarket shelf is pretty steady when I go to get some chocolate. What role exactly are they playing in shaping this overall chocolate market? And yeah, then what role do they play in the deprivation of the cocoa farmers? The price of chocolate does vary actually quite a lot.