Definition
An Immediate or Cancel Order (IOC) executes immediately, filling all or part of the order, and cancels any remaining unfilled portion.

Key Takeaways

  • An Immediate or Cancel Order (IOC) executes immediately, filling all or part of the order, and cancels any remaining unfilled portion.
  • IOC orders offer flexibility by allowing either market or limit orders but only require a partial fill.
  • Investors use IOC orders to avoid partial fills at varying prices in fast-moving markets.

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Immediate or Cancel (IOC) orders execute immediately and cancel any unfilled portion, useful for quickly executing trades in a fast-moving market. They can be submitted as either limit or market orders, offering flexibility in trading. IOC orders allow partial fills, unlike Fill or Kill (FOK) and All or None (AON) orders. Investors use IOC to limit risk and avoid orders being filled at varying prices.

What Is an IOC?

An immediate or cancel order (IOC) is an order to buy or sell a security that should execute immediately and cancel if any portion of the order remains unfilled. An IOC order is one of several time-in-force orders that specify how long an order remains active and when an order should be canceled. Other such orders include fill or kill (FOK), all or none (AON), and good ‘till canceled (GTC). Most online trading platforms support placing IOC orders manually or integrating them into automated strategies.

How IOC Orders Work

Investors can submit either a “limit” or “market” immediate or cancel order (IOC) depending on their specific execution requirements. An IOC limit order is entered at a particular price, whereas an IOC market order has no price attached and transacts with the best offer price for a buy and the best bid price for a sell.

IOC orders differ from other duration orders in that they only require a partial fill, whereas both FOK and AON orders must be filled in their entirety or canceled. GTC orders remain active until executed in the market or canceled by the client, although most brokers cancel them between 30 and 90 days.

Ideal Scenarios for IOC Orders

Investors typically use IOC orders when submitting a large order to avoid having it filled at varying prices. An IOC order automatically cancels any part of the order that doesn’t fill immediately. Assume a trader places an IOC order to purchase 5,000 shares of International Business Machines Corporation (IBM). Any portion of the 5,000 shares not purchased immediately is automatically canceled. Those who trade several stocks throughout the day may use an IOC order to minimize the risk of forgetting to cancel an order at the close.

Tip

IOC orders help investors to limit risk, speed execution and provide price improvement by providing greater flexibility.

Real-World Examples of IOC Orders

Imagine that an investor places an IOC market order for 1,000 shares of Apple Inc. (AAPL). The order book lists 2,000 shares bid at $170.95 and 500 shares available at $171.00. The order would immediately fill 500 shares at the offer price ($171) and cancel the unfilled portion of 500 shares.

Another investor places an IOC limit order for 1,000 Apple shares at $169 at market open when the stock is offered at $170. In the afternoon, the S&P 500 drops slightly and a seller offers 700 AAPL shares at $169. The IOC order, however, would not be filled because it was canceled immediately after not being filled earlier in the day.

What Are the Benefits of Using IOC?

IOC limit orders protect against getting a bad fill in a fast-moving or illiquid market. On the other hand, IOC market orders ensure a complete or partial execution in a strongly trending stock with heavy buying demand.

How Does IOC Affect Market or Limit Orders?

A market order is an order to buy or sell a stock at the best available price and will be executed immediately. A limit order is an order to buy or sell a stock at a certain price or better. Market and limit orders may include timing restrictions and other trading instructions like IOC. 

What Does Time in Force Mean for Market Traders?

Traders use time-in-force instructions when placing a trade to indicate how long an order will remain active before it is executed or expires.

The Bottom Line

An immediate or cancel order (IOC) is an order to buy or sell a security that should be executed in full or part immediately and then be canceled if any portion remains unfilled. It is an example of time-in-force orders which include Fill or Kill (FOK) and All or None (AON). An IOC differs from FOKs and AONs in that it allows partial fills.

An IOC helps investors manage risk by preventing large orders from being filled at varying prices. IOC limit orders protect investors during a fast-moving market. IOC market orders ensure a complete or partial execution in a strong market with high demand.

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