Immediate or Cancel (IOC) Order
An IOC order executes as much as possible immediately, then cancels any unfilled portion. It's designed for traders who need instant execution and won't wait for the market to come to them.
In plain English: "Fill what you can right now, cancel the rest—I'm not waiting."
What Is an Immediate or Cancel Order?
An Immediate or Cancel (IOC) order is a time-in-force instruction that tells your broker:
- Execute as much of this order as possible right now at the current available price.
- Any portion that cannot be filled immediately gets automatically cancelled.
- The order will never sit in the market waiting for a better price.
IOC orders are perfect when you need execution speed over completeness—you'd rather get partial fills now than wait for the full order to fill later.
How IOC Orders Work
When you submit an IOC order, the execution happens in milliseconds. Here's what occurs:
IOC Execution Flow
-
1
Order Submission You submit a buy or sell order with IOC time-in-force at a specified price (or market price).
-
2
Instant Matching The broker/exchange checks available liquidity at your price level and executes whatever is available.
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3
Immediate Cancellation Any unfilled quantity is cancelled automatically—it won't remain as a pending order.
The entire process happens in fractions of a second. You'll receive a fill confirmation (partial or full) almost instantly.
📊 Example: IOC with Partial Fill
You want to buy 100,000 units of EUR/USD at 1.0850 using an IOC order.
Available liquidity at 1.0850: Only 60,000 units
Result:
- 60,000 units are filled immediately at 1.0850.
- 40,000 units are automatically cancelled (no liquidity available).
- Your position is now 60,000 units—no pending order remains.
With a regular limit order, those 40,000 units would sit in the market waiting. With IOC, they're gone immediately.
IOC vs FOK vs GTC: What's the Difference?
These three time-in-force options serve very different purposes. Here's how they compare:
| Feature | IOC | FOK | GTC |
|---|---|---|---|
| Partial Fills | ✅ Allowed | ❌ Not allowed | ✅ Allowed |
| Duration | Instant only | Instant only | Days/weeks |
| Unfilled Portion | Cancelled | Entire order cancelled | Stays active |
| Best For | Quick partial execution | All-or-nothing trades | Waiting for specific levels |
| Risk | May only get partial fills | May get no fill at all | Market may move away |
⚠️ Key Distinction
IOC: "Get me whatever you can right now, cancel the rest."
FOK: "Get me everything or get me nothing—no partial fills."
GTC: "Keep trying until you fill it or I cancel it."
When to Use IOC Orders
✅ Ideal Situations
- Fast-moving markets: When prices are changing rapidly and you need to act now.
- News trading: Entering positions during high-impact announcements when liquidity varies.
- Scalping: When you need immediate execution for short-term trades.
- Reducing exposure: Exiting a position quickly, even if partially.
- Testing liquidity: Checking how much volume is available at a specific price.
❌ Less Suitable For
- Building large positions where you need the full quantity.
- Swing trading with specific entry levels that may take days to reach.
- Illiquid markets where partial fills would be too small to be useful.
- Strategies requiring precise position sizing.
Practical IOC Order Scenarios
Example 1: Scalping During NFP
Scenario: Non-Farm Payrolls just released. EUR/USD spikes to 1.0900. You want to sell into the spike.
Result: Only 30,000 units available at 1.0900. You get filled on 30,000, the remaining 20,000 is cancelled. Price continues moving—but you're already in with what you could get.
Example 2: Quick Exit on Reversal Signal
Scenario: You're long 100,000 GBP/USD. A bearish engulfing candle forms and you want out immediately.
Result: 85,000 units fill at 1.2650, 15,000 at 1.2648 (slight slippage due to liquidity). You're completely out—no waiting, no hoping.
Example 3: Partial Fill Accepted
Scenario: You want to buy gold at $1,950 but don't want to chase higher prices. You're okay getting less than your full size.
Result: 4 lots fill at $1,950.00. The remaining 6 lots are cancelled as price moves to $1,951. You have a smaller position than planned, but at your exact target price.
Advantages and Disadvantages
✅ Advantages
- Speed: Immediate execution without waiting.
- No stale orders: Won't fill at outdated prices later.
- Flexibility: Accepts partial fills when full liquidity isn't available.
- Control: You know immediately what you got.
- Price certainty: Fills at current market, not a future unknown price.
⚠️ Disadvantages
- Partial fills: You may not get your full intended position.
- Multiple orders needed: May need to submit several IOCs to build full size.
- Slippage risk: In volatile markets, even IOC orders can slip.
- Complexity: Managing partial positions adds operational overhead.
- Not for all strategies: Some strategies require precise position sizing.
IOC Support Across Platforms
IOC orders are widely supported, but implementation varies:
- MetaTrader 4/5: IOC is often the default for market orders. Some brokers label it differently.
- cTrader: Full IOC support with clear time-in-force selection.
- TradingView (broker integration): Depends on connected broker—check their order panel.
- Institutional platforms: Full IOC support with detailed fill reports.
- Exchange trading: Standard on most stock and futures exchanges.
💡 Tip
If your platform doesn't explicitly show "IOC," check if there's a "time-in-force" dropdown. Some platforms use terms like "Immediate" or "Execute and Eliminate" for the same functionality.
Frequently Asked Questions
What is an Immediate or Cancel (IOC) order?
An IOC order is an instruction to execute as much of the order as possible immediately at the current price, then automatically cancel any unfilled portion. Unlike regular orders that may wait in the market, IOC orders demand instant action.
What is the difference between IOC and Fill or Kill (FOK) orders?
IOC orders allow partial fills—whatever quantity can be executed immediately is filled, and the rest is cancelled. FOK orders require the entire order to be filled immediately or the whole order is cancelled. IOC is more flexible; FOK is all-or-nothing.
When should I use an IOC order?
Use IOC orders when you need immediate execution at the current price, are willing to accept partial fills, want to avoid orders sitting in the market, or are trading in fast-moving or volatile conditions where prices change rapidly.
Can IOC orders experience slippage?
Yes, especially in volatile markets. While IOC orders execute immediately, if liquidity is thin or prices are moving fast, you may experience some slippage from your intended price. The trade-off is speed over price precision.
What happens if no liquidity is available for my IOC order?
If there's zero liquidity at your specified price, the entire IOC order is cancelled immediately. You'll receive a notification that the order was not filled. No portion of the order will sit pending in the market.
📝 Key Takeaways
- IOC orders execute immediately and cancel any unfilled portion—no waiting.
- They accept partial fills, unlike Fill or Kill (FOK) orders which are all-or-nothing.
- Best for fast-moving markets, news trading, scalping, and quick exits.
- Trade-off: you prioritize speed over getting your full intended position size.
- IOC orders never sit in the market—they execute or cancel instantly.
- Most platforms support IOC, but the terminology may vary—look for "time-in-force" options.
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