what is an ioc 
an immediate or cancel order ioc is an order to buy or sell a security that will execute all or part immediately and then cancel any unfilled portion of the order an ioc order is one of several duration or time in force orders that investors can use to specify how long the order remains active in the market and under what conditions the order is canceled other commonly used duration order types include fill or kill fok all or none aon and good till canceled gtc most online trading platforms allow ioc orders to be placed manually or programmed into automated trading strategies 