A derivative is a financial instrument whose value is derived from an underlying asset such as a stock, bond, commodity, or currency. Derivatives include futures, options, and swaps. There are three main types of traders in derivatives markets - hedgers who use derivatives to reduce risk, speculators who trade for profit, and arbitrageurs who take advantage of temporary price differences. Derivatives can be traded over-the-counter between two parties or on an exchange where they are standardized and require margin payments.