An oligopoly's a market form in which a market or industry's dominated by a small number of sellers (oligopolists). The word's derived from the Greek oligo 'few' plus -opoly as in monopoly and duopoly. Because there're few participants in this type of market, each oligopolist's aware of the actions of the others. The decisions of one firm influence, and are influenced by, the decisions of other firms. Strategic planning by oligopolists always involves taking into account the likely responses of… (More on Oligopoly)