Immediate Or Cancel Order (IOC) An order requiring that all or part of the order be executed immediately after it has been brought to the market. Any portions not executed immediately are automatically cancelled. Investopedia Says: This is used for large orders where filling quickly can be difficult. Related Terms: All Or None Order Fill or Kill Good This Week - GTW Limit Order Market If Touched - MIT Market Order Split Block Pricing Stop Order Sweep-To-Fill Order |