An order to a broker to conduct a transaction on the assumption that a related transaction is conducted. The related transaction may occur before, after, or at the same time as the contingent order. That is, an investor may give an order to his/her broker to buy Stock A contingent upon the sale of Stock B. A common example of a contingent order is a buy-write, in which an investor orders his/her broker to buy a security and at the same time write an option with that security as the underlying asset.
A special type of security order that instructs the broker to take some action only in the event that something else has occurred. An example would be an order to sell call options on Westinghouse common stock only after shares of Westinghouse have been purchased at a specified limit price.