Immediate or Cancel (IOC)
An order that executes as much as possible immediately, then cancels any unfilled portion.
Immediate or Cancel (IOC) instructs the exchange to fill whatever quantity is available right now at the specified price (or better), then cancel the rest. Unlike FOK, partial fills are accepted.
IOC is commonly used by algorithmic traders and institutional desks that want quick execution without leaving a standing order visible in the book.
In retail trading, IOC is useful when you want partial exposure now but do not want a resting limit order signaling your intent to the market.