When you're eating a chocolate bar, there's a good chance you're not thinking about the complex commodity market that allows cocoa beans to make it into a tasty snack. But obviously cocoa trading is a huge business. On this week's Odd Lots podcast, we speak to professor Kristy Leissle, the author of the book “Cocoa,” about how this commodity market really works. She explains to us where it's grown, how pricing's determined, and the role of the major confectionery buyers in this market.