http://en.wikipedia.org/wiki/Perfect_information Perfect information describes the situation when a player has available the same information to determine all of the possible games (all combinations of legal moves) as would be available at the end of the game. In Game theory a game is described as a game of perfect information if perfect information is available for all moves. Chess is an example of a game with perfect information as each player can see all of the pieces on the board at all times. Other examples of perfect games include tic tac toe, irensei, and go. Games with perfect information represent a small subset of games. Card games where each player's cards are hidden from other players are examples of games of imperfect information. In microeconomics, a state of perfect information is assumed in some models of perfect competition. That is, assuming that all agents are rational and have perfect information, they will choose the best products, and the market will reward those who make the best products with higher sales. Perfect information would practically mean that all consumers know all things, about all products, at all times, and therefore always make the best decision regarding purchase. In competitive markets, unlike game-theoretic models, perfect competition does not require that agents have complete knowledge about the actions of others; all relevant information is reflected in prices. The concept of perfect information has often been criticized by the various schools of heterodox economics. Trading is a game we all play in various forms. So do you think trading is a perfect or imperfect information game?