An Immediate or Cancelled Order (IOC) allows bidders to buy or sell a security as soon as the order is placed on the market. Otherwise, the order is removed from the market. Orders may be partially matched and any non-matching parts of the order will be canceled immediately.
An IOC is a "long" order, meaning that the investor decides how long that order will remain active in the market. In the case of an IOC, this is an order with "zero duration" because it takes only a few seconds from being placed to executing an order.
An IOC order can be placed as a limit or market order. A limit order means that you only sell/buy a security when it falls into a specific price category. A market order means that the trade is executed at the current price.
