Used in context of general equities. Order giving a broker a choice between two courses of action either to buy or sell, never both. Execution of one course automatically makes the other inoperative. An example is a combination buy limit/buy stop order, wherein the buy limit is below the current market and the buy stop is above. If the order is for one unit of trading when one part of the order is executed on the happening of one alternative, the order on the other alternative is to be treated as cancelled. If the order is for an amount larger than one unit of trading, the number of units executed determine the amount of the alternative order to be treated as cancelled. Either-or order.