In fast-moving markets, timing can influence how a trade gets executed. This is where certain order types, like the Immediate or Cancel (IOC) order, become useful. IOC orders help traders attempt execution instantly without leaving orders pending in the order book.
What is an IOC Order?
An IOC (Immediate or Cancel) order is a type of order where the trade must be executed immediately, either fully or partially. Any portion of the order that cannot be executed instantly is automatically cancelled.
In simple terms:
- Instant execution attempt
- Partial fills allowed
- Remaining quantity cancelled
For example, if you place a buy IOC order for 1,000 shares at a specific price:
- If 600 shares are available at that price, those get executed immediately.
- The remaining 400 shares are cancelled instantly.
- The order does not remain pending in the market.
Why Do Traders Use IOC Orders?
IOC orders are commonly used when traders want control over execution timing rather than waiting in the order book.
Traders use IOC orders for:
- Fast-moving markets where prices change quickly
- Avoiding orders remaining visible in the order book
- Precision trading when only the available quantity matters
- Reducing the uncertainty of delayed execution
IOC orders ensure that trades are executed immediately or cancelled.
When Can IOC Orders Be Used?
IOC orders are generally used when:
- Quick execution is required
- The trader does not want pending orders in the market
- Trading in volatile or fast-moving markets
- Partial execution is acceptable
- Market liquidity is uncertain
Liquidity plays an important role in IOC orders because execution depends on the available quantity at that moment.
IOC Order vs Day Order
| Feature | IOC Order | Day Order |
| Order Validity | Immediate only | Valid for entire trading day |
| Execution Time | Immediate | Anytime during trading day |
| Unexecuted Portion | Cancelled instantly | Remains pending |
| Order Book | Does not remain | Remains in the order book |
| Suitable Market | Volatile/fast markets | Normal markets |
How to Place an IOC Order on Flattrade?
Placing an IOC order on Flattrade is simple:
- Log in to the Flattrade App or Web platform
- Search for the stock
- Click Buy or Sell
- Select Product Type
- Enter Quantity and Price
- Choose Order Validity as IOC
- Place the order
The order will either be executed immediately (fully or partially) or cancelled automatically.
Conclusion
IOC orders are useful in situations where immediacy is important. They allow traders to attempt execution instantly without leaving orders open in the market.
This order type is particularly useful in fast-moving markets where traders want quick execution and do not want pending orders.
Understanding different order types, including IOC orders, helps traders execute trades more efficiently and with better control.


