<p>An Immediate or Cancel (IOC) order is a type of market or limit order that must be executed as soon as it is entered into the trading system; any portion of the order that cannot be filled immediately is automatically cancelled. Unlike a Fill‑or‑Kill order, an IOC allows partial execution, meaning the broker will fill whatever volume is available at the specified price (or better) and discard the remainder.</p>

<p>IOC orders are useful for traders who want to avoid unwanted exposure from lingering unfilled quantities, such as when attempting to sweep liquidity across multiple venues or when entering a position in a fast‑moving stock. For example, placing an IOC limit buy for 10,000 shares at $50.00 will execute only the shares presently offered at that price, and any unfilled shares are instantly removed from the book.</p>