Immediate-or-cancel order

An immediate-or-cancel order (IOC order) is one which has to be executed immediately and fully, or as fully as possible. Non-executed parts of an IOC order are deleted without entry in the order book.

Fill-or-kill order

A fill-or-kill order (FOK order) is one which has to be executed and fully or not at all. If immediate and full execution is not possible, the FOK order is deleted without entry in the order book.

Book-or-cancel order

A book-or-cancel order (BOC order) is one that is entered in the order book if it cannot be executed immediately. If a book-or-cancel order can be executed immediately, the order is rejected.

BOC orders in the order book are deleted at the start of an auction. During the auction, incoming BOC orders are rejected.

A BOC order is intended to ensure the passive execution of the order. This makes the book-or-cancel order particularly meaningful in the case of securities for which, with regard to the explicit transaction costs, passive execution (an order is already in the order book on execution) is preferred to aggressive execution (an order is entered, can be executed immediately and thus drains liquidity from the order book).