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Fill or kill

Fill or kill (FOK) is a condition a trader or investor can include in his/her purchase or sale of a stock

Expanded Definition

FOK, as it's usually referred, to as is pretty easy to understand. Simply put when a trader uses FOK on a buy order he is telling his broker to either buy all the shares he wants in one trade or don't buy it at all. If the stock can't be found immediately the order is canceled. The same is true for FOK sell orders. Often times brokers fill partially fill orders in order to try to get the most advantageous price for their customers, especially those using limit orders. FOK prohibits a broker from doing that.

Use to Investors

This is seldom used and for good reason.FOK is the most restrictive order condition available. FOK orders are very difficult to get successfully executed and provide marginal benefit to the trader. Usually those traders who would even contemplate using a FOK prefer the additional flexibility that the similar all or none or immediate or cancel orders give.

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