Each commodity traded on the market is pictured to the left of the screen. At the top of the column are goods, followed by materials, with resources at the bottom.
Hot text will remind you of each commodity's name. Information on the screen includes the current world price and the amount you have available in your stockpile.
Near the top of the right wooden border is a number under a ship icon. This represents your merchant marine. With rare exceptions, you are unable to buy and sell more total items in one turn than this number.
You may also occasionally see other icons appear in the border areas. When this occurs it means your industry or your workers have a particular demand for that item.
