What does an IOC order specify?

An Immediate Or Cancel (IOC) order is a type of order that requires immediate execution of any part of the order that can be filled at the current market price. If the order cannot be immediately filled, the unfilled portion is canceled. This characteristic of requiring immediate action distinguishes IOC orders from other order types.

With an IOC order, traders aim to take advantage of current market conditions without waiting for additional matching orders. This is particularly useful in fast-moving markets or when liquidity is important. The focus on immediate execution ensures that the trader can act on price changes dynamically, which can be critical for trading strategies that rely on quick responses.

Other types of orders, such as those that remain valid for the entire trading day or that specify conditions for execution (like market price only or specific auction times), do not have the same priority on immediacy as an IOC order does.