A contingency order is a buy or sell order that is executed from a broker's trading platform only when specific, trader-defined conditions have been met. These prerequisite conditions range in scope and depth.

附条件指令指的是仅当交易者规定的特定条件获得满足时在经纪人的交易平台得到执行的买盘或卖盘。这些先决条件在范围和深度方面各不相同。

A simple example of a contingency order is a limit order to buy or sell a security at a specified price or better. A more complex contingency order, known as a conditional order, might specify buying a defensive stock when the S&P 500 Index falls below a certain price.

简单来说，附条件指令就是按特定价格或更好的价格买卖证券的限价指令。复杂一点，可能会规定在标准普尔500指数低于特定价格时购买防卫型股票。

Conditional orders can involve even more complex criteria. For example, a trader can make the purchase of an option dependent on two or more variables, such as the price of the underlying stock and the price of the option contract itself. The number and complexity of conditions to the order is limited only by the broker's platform and the trader's imagination.

附条件指令可能会涉及更加复杂的指标。比如，交易者可以基于两个或以上可变因素（如基础股票价格和期权合约本身的价格）购买期权。指令所附条件的数量和复杂程度仅以经纪人平台和交易者的想象力为限。

In a broad sense, any order that uses a specific condition to trigger its execution could be considered a contingency order. Under that definition, any order other than a market order would be considered a contingency order. However, most brokerage platforms refer to contingency orders as something that has a more complex, or even a conditional, execution.

广义上讲，利用特定条件触发执行的指令都可以视为附条件指令。根据这个定义可以得出，市价指令以外的任何指令可以被视作附条件指令。但是，大多数经纪业务平台认为，附条件指令指的是执行更加复杂或者附加条件的指令。

Perhaps the simplest form of a contingency order is a limit order. This specifies that an order will only be executed at (or better than) a specified price. For a buy limit order, this will represent a pre-determined minimum price, and for a sell limit order a pre-determined maximum. Actual orders may be filled at a price more favorable than the specified limit, but never worse.

或许，附条件指令最简单的形式就是限价指令，即按特定价格或更好的价格执行的指令。就买入限价指令而言，指的是预先确定的最低价格；就卖出限价指令而言，指的是预先确定的最高价格。实际指令可能会以比规定的限价更有利的价格执行，但是绝对不会以更差的价格执行。

A stop-loss order can also be viewed as a contingency order, because it does not become a market order until the price of the security being sold reaches a predetermined level. A stop loss is very useful when applied to options trading, as well as establishing exit points in stock positions during a bear market. Other modifications to stop loss orders include the trailing stop.

止损指令也可视为附条件指令，原因在于，当出售的证券价格达到预先确定的水平之时，止损指令即变为市价指令。在期权交易中止损非常实用，以及在空头市场建立头寸之前预先设定退出的点位。止损指令的其他变型包括追踪止损。

An all or none (AON) order is one that executes contingent on getting the full order size executed at once. If a trader wants to buy 10,000 shares of Company XYZ all or none, then they would refuse an execution of anything less than the full 10,000 shares.

全部成交否则全部取消（AON）指令指的是交易指令必须完全成交，否则取消。如果交易者希望购买某公司10,000股股票，限制条件为AON指令，那么低于10,000股的指令不予执行。

An immediate or cancel (IOC) order is contingent upon being executed immediately. If an order cannot be filled in whole or in part within a very short period of time, the order is canceled. Say a trader wants to buy 10,000 shares of Company XYZ for a limit price of $20 and specified immediate or cancel. If there are only 2,500 shares on offer at $20, other sellers will have to come in. But since it is designated IOC, only the 2,500 shares may end up trading.

立即成交否则取消（IOC）指令指的是交易指令要么全部成交，要么部分等量成交，否则即行取消。举例来说，如果交易者希望购买某公司10,000股股票，限价为20美元，限制条件为IOC指令，但是只有2,500股按20美元出售，鉴于指定了IOC指令，最终仅有2,500股进行交易。

A fill or kill (FOK) order is one that combines all or none and immediate or cancel. In the example above, the order would only be executed if all 10,000 shares could be filled in a very short period of time.

全部成交否则取消（FOK）指令属于AON指令和IOC指令的结合，即交易指令要么全部成交，要么立即取消。在上述举例中，若指定的是FOK指令，那么只有10,000股全部交易时才能执行指令。

来源：

Investopedia