Pit Market Trading
Sellers
You can each sell one bond during each trading period. The number on your card is the dollar cost that you incur if you make a sale. You will be required to sell at a price that is no lower than the cost number on the card. Your earnings on the sale are calculated as the difference between the price that you negotiate and the cost number on the card. If you do not make a sale, you do not earn anything or incur any cost in that period. If you mistakenly agree to a price that is below your cost, then the trade will be invalidated when you come to the trading desk; your card will be returned, and you can resume negotiations.
Example: Suppose that your card is a 2 of hearts and you negotiate a sale price of $3.50. Then you would earn $3.50 - $2 = $1.50. You would not be allowed to sell at a price below $2 with this card.
Think of it this way: it's as if you knew someone who would sell you the bond for a price that equals your cost number, so you can keep the difference if you are able to resell the commodity for a price that is above the acquisition cost. In other words, you are buying low and selling high.