Immediate or canceled order
Immediate or canceled order (IOC order)
An order from a broker to buy or sell a security or derivative, usually in large quantities, in which investors have a short period of time to partially or completely fulfill the order before it is cancelled. An IOC may be considered the opposite of a good 'til cancelled (GTC) order; it differs from a fill-or-kill (FOK) order because an IOC may only be partially filled, while an FOK must be entirely filled or the whole offer is void. An IOC is considered a type of day order, but has a much shorter time frame. See also: All-or-none offering.