FAK order指FAK订单，全称为“Fill and Kill”，是立即成交和撤销指令。指订单在指定价位成交，且剩余订单自动被交易所撤消。 A Fill and Kill Order (FAK) is an order type that is commonly used for bulk orders. This allows you to place a buy or sell order at your preferred price (limit price) and any unfilled amount or portion will be canceled after the order has been executed.

FAK订单能够使全部或部分订单有机会在指定价位立即成交，让交易者以期望价格持有头寸，同时节约交易者对未成交订单的管理成本。

FOK order指FOK订单，全称为“Fill or Kill”，是立即全部成交否则自动撤销指令。

指在限定价位下达指令，如果该指令下所有申报手数未能全部成交，该指令下所有申报手数自动被交易所系统撤销。 Fill or kill (FOK) is a conditional type of time-in-force order used in securities trading that instructs a brokerage to execute a transaction immediately and completely or not at all. This type of order is most often used by active traders and is usually for a large quantity of stock. The order must be filled in its entirety or else canceled (killed).

FOK订单能够使全部订单有机会在指定价位立即成交，让交易者以期望价格持有头寸，同时节约交易者对未成交订单的管理成本。FOK订单还能有效降低市场人为撤单量并大幅提高市场运行效率。

以下为相关双语示例，供参考：

Fill-or-kill orders and fill-and-kill orders which are to be executed (or not) immediately, the order attribute "T+1" will not be applicable and will be ignored. 

至于须实时执行（否则全部取消）的“全部成交否则自动撤销指令”及“立即成交和撤销指令”，“T+1”买卖盘选项并不适用，可以略去。 

On some exchanges, an FOK should be executed within a few seconds of it being shown to the trading community. In this context, the market or limit order FOK is treated similarly to an "all or none" order with the exception that it is immediately canceled if not completely filled. 

在一些证券交易所，“立即全部成交否则自动撤销指令”应在向交易团队出示后几秒内尽快执行。在此情况下，市价委托或限价委托的FOK订单将被视为类似于“整批委托”订单，但其在未完全执行的情况下立即取消的除外。