What does Fill or Kill mean?
A Fill or Kill order is a type of purchase order made on an exchange. The order will specify what price to buy at, how much to buy, and how long to keep the order open.
The order then remains open, with the exchange looking to match the order to a seller with the same or better criteria, until the end date for the order.
If the exchange finds a suitable seller the order is filled, but if no match is found by the specified end date the order is cancelled, or killed. So, the fill or kill order specifies an order to be filled according to a set of rules, and if it can’t be filled in accordance with those rules it is killed.