Immediate-or-cancel (IOC) is an order type used in financial markets to execute a trade immediately or cancel it if it cannot be executed immediately. When an IOC order is placed, it instructs the broker or exchange to execute the trade as soon as possible, either in full or partially, and any portion of the order that cannot be immediately filled is canceled.

IOC orders are commonly used by traders who want to ensure immediate execution of their orders but are willing to accept partial fills if the entire order cannot be matched at once. This order type is particularly useful in fast-moving markets or when traders want to avoid slippage, which is the difference between the expected price of a trade and the actual executed price.

It's important to note that IOC orders prioritize immediacy over completeness. If the entire order cannot be executed immediately, the remaining portion is canceled. Traders should carefully consider the liquidity and volatility of the market before using IOC orders to ensure their trading strategy aligns with the characteristics of the order type.

Immediate-or-Cancel (IOC) is a type of order used in trading where all or part of the order must be executed immediately, and any unfilled portion is cancelled. It is commonly used in fast-moving markets like forex, stocks, and crypto to ensure quick execution without waiting for the entire order to be filled. IOC orders help traders avoid slippage and price changes, especially when placing large trades. For example, if a trader places an IOC order to buy 1,000 shares and only 600 are available at the desired price, those 600 will be executed instantly, and the remaining 400 shares will be cancelled. This order type offers more control over execution and is useful in volatile or low-liquidity environments.