Community Submission - Author: John Ma

Some exchanges and trading platforms offer a type of order known as “Fill or Kill Order” (FOK). The term refers to the idea that an order must be filled immediately in its entirety or not executed at all. It is closely related to the “All or Nothing” (AON) order type, which refers to an order that must be filled in its entirety or not at all. Unlike, FOK orders, however, AON orders don’t have a specific focus on the immediate point in time.

Fill or Kill orders are often used when a trader doesn’t want to accept partial delivery of assets. For instance, when they have a time-based demand to fill their orders on distinct and unlinked markets or exchanges. So a FOK order would allow them to create multiple orders and wait for one to be fully executed without taking the risk of receiving partial fills. After one of the orders is filled in its entirety, the trader is able to cancel the remaining ones.

As an example of a Fill or Kill use case, consider this following scenario:

Alice wants to set up an altcoin masternode immediately, but one of the requirements for running a masternode is that she must hold 1000 units of that particular cryptocurrency. If time was not a limiting factor, Alice could place numerous buy orders until the 1000 threshold is eventually reached. However, since she wants the masternode up and running without too much delay, she can place multiple Fill or Kill buy orders for 1000 units of the altcoin (in different exchanges). This way, Alice will only pay for the altcoins if she gets the 1,000 units she wants and this allows her to cancel any order that is not filled in its entirety.