What is IOC in the Share Market?

Last Updated: 5 Sep 2025

Global financial markets saw a crash because of the Covid-19 crisis for a short period. While long-term investors curtailed their activities, intra-day traders continued to trade in the stock market. This is because traders often try to profit from such a volatile market.Millions of trades take place at any given time in the market, and an active trader may have several active trades simultaneously. It can become tedious to track all the unexecuted positions. That’s where IOC comes into the picture. Let’s take a detailed look at what is IOC in trading.

What is IOC?

A brief understanding of the share market is necessary to understand IOC in trading. The IOC (Immediate or Cancelled) allows an investor to buy or sell a share as soon as the order is placed in the market, failing which the order will be removed from the system. It is a duration order and cancels out if it is not executed immediately.

For instance, if you place an immediate or cancel order for 100 shares of XYZ, but 100 shares are not available in the market at the moment. The order will cancel out as soon as you place it. An IOC order does not create active positions, it is either executed or gets cancelled out. One doesn’t have to intervene to cancel the order, it is an automatic process. IOC is essentially a duration order, which is a category of orders that have a specified duration. In the case of IOC, the duration is a few seconds. Now that you know what is IOC in share market, let’s understand why it’s needed.

What is the Need for an IOC?

One may enter the market by opening a free trading account, but without a clear understanding, it can be difficult to generate profits. The threshold for entry has reduced with the advent of online trading accounts, which is extremely easy and convenient to open. So, after getting an online trading account, when you place a buy or sell order, there is no certainty of the order getting executed. There might be a mismatch between the number of people trying to buy a stock and people trying to sell it. If you place a buy order, but there is a lack of sufficient sellers, you may have to wait for the completion of the order. The waiting time creates many active positions, which may sometimes be confusing or difficult to track.

Flexibility with IOC

An investor can set the IOC as a market or limit order.

• When you place a market order, the shares are bought or sold at the prevailing market prices.
• With limit orders, you can specify the price at which you want to buy or sell a particular share.

In the case of immediate or cancel orders, there is also a provision of partial fulfilment of the order. Suppose you place an IOC order to buy 100 shares of ABC company. There are not enough shares of ABC to be sold at the moment, but since an IOC order is executed immediately, you will be allotted 20 shares, while the order for the balance of 80 shares will be cancelled automatically

When is an IOC Order Effective?

• An IOC order is effective when immediate execution is necessary. It must be filled instantly, or the unfilled portion is cancelled, making it suitable for traders who need quick action in volatile markets.
• IOC orders are ideal during periods of high market volatility. They allow traders to capitalise on rapid price movements without leaving lingering orders that could result in unfavourable fills.
• An IOC order helps reduce market impact while placing large orders because it ensures that only available shares are bought at once and any unfilled portions are cancelled.

When to Use an IOC Order?

An IOC in share market is best used when you need quick execution of trades without leaving unfilled orders in the market. It is ideal for large orders to minimise market impact, especially in volatile conditions. Additionally, IOC orders are useful when managing multiple trades simultaneously, as they reduce the risk of forgetting to cancel pending orders. This order type also allows traders to set specific price limits while ensuring immediate action on available shares.

Difference Between Day Order and IOC Order in Trading

A Day Order is all about waiting for the price you want, while an Immediate-or-Cancel (IOC) Order is more impatient, where you get everything at that moment. These two order types help traders manage how long their buy or sell requests stay active. Below are two quick connecting thoughts before we compare them:

• While both instructions control time, they cater to very different trading styles – patient versus urgent.
• Knowing when to use each can save money, manage risk, and keep your trading plan on track.

Now let’s understand in detail how they differ –

Point of Difference	Day Order	IOC Order
Life span	Good only until the market closes on the same day; if not filled, it disappears.	Valid for a split-second: any portion not executed instantly is cancelled.
Partial fills	Will keep trying all day until the full quantity trades or the session ends.	Accepts an immediate partial fill; unfilled balance is dropped.
Use case	Suitable when you believe the price will hit a target sometime today.	Ideal when quick entry/exit matters more than full quantity.
Market impact	Lower urgency; less slippage risk if placed away from the current price.	Higher urgency; may accept current quotes, risking slippage.
Example	“Buy 100 shares at ₹150 today.”	“Buy up to 100 shares at ₹150 right now – fill what you can, cancel the rest.”

Advantages & Disadvantages of IOC Order

• First, they move at the speed the market moves. As soon as the instruction reaches the exchange, any shares that match the stated price are bought or sold, which is valuable during quick price swings.
• Second, the trader chooses both the number of shares and the price, so the same order type works equally well for entering or exiting a position.
• Third, partial execution is allowed: the system completes the portion that is available and removes the rest, ensuring that no unfinished part lingers on the order book. This automatic cancellation also supports careful risk control because it keeps the trader from being exposed to later price changes.
• Finally, IOC instructions improve efficiency. A trader can place several orders during a session without having to watch each one constantly, cutting down on manual checks and lowering the chance of mistakes.

Here are the disadvantages of IOC in share market –

• First, the instruction may be filled only in part; any shares that are not matched vanish, so you could miss out on building the full position you planned.
• Second, setting up an IOC order is more demanding than using a simple market or limit order. You must choose an exact price and act quickly, which requires extra time and concentration.
• Third, certain brokers treat IOC orders as a special service and apply an additional fee, raising your trading costs.
• Fourth, placing a large IOC order can move the price of a thinly traded stock because the sudden rush of demand or supply may sway the market.
• Finally, if you enter many IOC orders in one session, tracking which trades went through and which were cancelled becomes challenging, making it harder to see an accurate picture of your portfolio.

Example of IOC Order

An Immediate or Cancel (IOC) order asks the market to act at once. Whatever part of the order can be matched right away is carried out, and any shares that cannot be matched are cancelled immediately.

Imagine you send an IOC limit order to buy 1,000 shares at ₹4,000 each. If only 600 shares are available at that price, the system buys those 600 and cancels the other 400 on the spot. No part of the request stays open.

IOC orders suit fast-moving markets because they let traders secure the shares that are on offer without delay and remove the risk of leaving unfilled pieces hanging in the order book. For anyone who values speed and certainty, an IOC instruction can be a practical choice.

How To Place IOC Order

Placing an IOC order is straightforward once you grasp the logic behind instant or cancel. Follow these steps to practise safely:

1.Open Your Trading Platform

Log in to your broker’s web or mobile app. Make sure you’re in the correct market (cash equity, futures, or options).

2.Select the Stock or Contract

Type the ticker symbol – for example, “INFY” for Infosys – into the search bar. Tap it to open the order ticket.

3.Choose Order Type

In the order ticket, you’ll see choices like Market, Limit, Stop-Loss, etc. Pick Limit if you care about price, or Market if you just want speed.

4.Set Quantity and Price

Enter how many shares or lots you’d like. If you choose a limit IOC, type the maximum price you’re willing to pay (for buys) or the minimum price you’ll accept (for sells).

5.Find the Time-in-Force Field

Look for a dropdown labelled Validity, Duration, or TIF. Options usually include Day, IOC, and sometimes GTC (Good-Till-Cancelled). Select the IOC option.

6.Review Margin Impact

The platform should display the required funds. Because IOC orders may execute only partially, the system blocks funds for the maximum amount first, releasing any extra immediately after processing.

7.Submit the Order

Double-check details (ticker, quantity, price, and IOC validity), then hit Place Order. Within milliseconds, the exchange matches as many shares as possible. Anything not matched is auto-cancelled.

8.Check Order Status

Navigate to the Orders tab. You’ll see either Complete (if fully filled) or Partial, along with Cancelled for the unfilled portion. Funds for the cancelled part return to your balance right away.

9.Use Case Tips

• IOC shines for fast-moving stocks or thin-liquid options where waiting could mean missing an opportunity.
• Pair it with limit prices to control slippage. For market IOC, be ready for sudden price jumps.

10.Practise in Demo Mode

Many brokers offer virtual trading. Try IOC orders there first, and you’ll gain confidence without risking real rupees.

By mastering IOC orders, you add a lightning-quick tool to your trading toolbox – perfect when every second (and every paisa) counts.

Conclusion

An immediate or cancel order (IOC full form in trading) can be immensely effective if used properly. One can execute multiple IOC orders without the need to track their status for a long time. However, it should be used sparingly as a large number of partially fulfilled IOC orders can disturb your calculations. To start trading using IOC orders, you can open an IIFL Capital Services Limited Demat and trading account, which is an all-in-one account, and you can make multiple investments through a single platform.

Frequently Asked Questions

Which is better, IOC or Day?

The choice between an IOC and a Day order depends on trading strategy. An IOC in share market is preferable for immediate execution, especially in volatile markets. At the same time, a Day order is suitable for traders waiting to fill their orders throughout the trading day. 

What are the benefits of IOC orders?

IOC in share market provides several benefits, including immediate execution, flexibility in trading strategies, and the ability to avoid market impact from large orders. They also allow for partial fills, minimising risk by cancelling unfilled portions quickly and enabling traders to act swiftly in dynamic market conditions.

What is the validity of an IOC order?

An IOC in the share market has no validity period; it must be executed immediately upon placement. If the order cannot be filled at that moment, any unfilled portion is automatically cancelled. This characteristic makes IOC orders ideal for traders seeking quick execution without lingering orders.

What are IOC and GTD trading?

IOC in share market requires immediate execution, while GTD (Good Till Date) orders remain active until a specified date or until they are executed. IOC orders focus on speed, whereas GTD orders allow traders to wait longer for their desired price without cancellation.

Which is better, IOC or Day?

The preference between IOC and Day orders hinges on trading goals. IOC in the share market is better for immediate execution in fast markets, reducing market impact. Conversely, Day orders are suitable for traders who prefer to wait for specific price targets throughout the trading day without immediate cancellation.