What are the order execution types available on Bybit contracts?

Bybit offers key order execution types—IOC, FOK, and Post Only—each designed for precise trade control, liquidity management, and fee optimization in contracts trading.

Aug 09, 2025 at 03:56 pm

Understanding Order Execution Types on Bybit Contracts

When trading Bybit contracts, users have access to several order execution types that determine how and when their trades are filled. These execution types are essential for managing risk, optimizing entry and exit points, and aligning trading strategies with market conditions. The primary execution types available on Bybit include Immediate or Cancel (IOC), Fill or Kill (FOK), and Post Only. Each of these serves a distinct purpose and interacts differently with the order book.

• Immediate or Cancel (IOC) ensures that an order is executed instantly for the available quantity at the specified price or better. Any portion of the order that cannot be filled immediately is cancelled automatically.
• Fill or Kill (FOK) requires the entire order to be filled at the specified price or better immediately, or else the entire order is rejected.
• Post Only places an order only as a maker, meaning it will not execute against existing orders. If it would execute immediately as a taker, the order is rejected or adjusted to maintain maker status.

These execution types are accessible in both Spot and Derivatives trading interfaces on Bybit, but their behavior may differ slightly depending on the contract type (e.g., USDT Perpetual, Inverse Perpetual, or Futures).

How to Set IOC Orders on Bybit

To place an Immediate or Cancel (IOC) order on Bybit:

• Navigate to the Contracts trading interface and select your desired market (e.g., BTC/USDT).
• Choose Limit or Market order type, then locate the Time in Force (TIF) dropdown menu.
• Select IOC from the options.
• Enter your price and quantity.
• Click Buy or Sell to submit the order.

Once submitted, the system attempts to match your order with existing liquidity on the order book. If partial execution occurs, the unfilled portion is immediately cancelled. This execution type is ideal for traders who want to avoid open resting orders and prefer fast execution with minimal market exposure.

It’s important to note that IOC orders can result in slippage if market depth is insufficient, especially for large orders. Also, IOC orders may incur taker fees if they match against existing maker orders.

Configuring Fill or Kill (FOK) Orders

Fill or Kill (FOK) orders are stricter than IOC and require full execution. To set a FOK order:

• Open the Bybit trading terminal and select the contract pair.
• Switch to Limit order mode (FOK is not available for Market orders).
• In the Time in Force section, choose FOK.
• Input your desired limit price and order size.
• Submit the order by clicking Buy or Sell.

The system checks whether the entire quantity can be filled at your specified price or better. If sufficient matching orders exist, the trade executes fully. If not, the entire order is rejected without partial fills. This is useful when entering large positions where price consistency is critical, such as in arbitrage or algorithmic trading strategies.

Traders should verify order book depth before placing FOK orders, as thin markets increase the likelihood of rejection. FOK orders are always taker orders and thus subject to taker fees.

Using Post Only Orders to Avoid Taker Fees

The Post Only execution type is designed to ensure your order contributes to market liquidity. To use it:

• Go to the order entry panel on Bybit.
• Select Limit order type.
• In the Time in Force menu, pick Post Only.
• Enter your price and amount.
• Click Buy or Sell.

If your limit price would cross the spread (i.e., match an existing order), Bybit automatically cancels the order or adjusts it to the best non-matching price, depending on platform settings. This guarantees you remain a maker, benefiting from lower or zero fees in some cases.

For example, if the best bid is $30,000 and you place a Post Only buy at $30,001, the order may be rejected because it would execute immediately. Instead, Bybit might adjust it to $30,000 or cancel it, depending on configuration.

Post Only is ideal for liquidity providers, market makers, and traders aiming to reduce trading costs over time.

Differences Between Execution Types in Practice

Understanding the practical differences between execution types helps avoid unintended outcomes:

• IOC allows partial fills and cancels the rest, making it suitable for urgent entries with flexibility.
• FOK demands full execution or nothing, useful for precision-based strategies requiring complete fills.
• Post Only prevents taker execution, favoring fee optimization and market-making behavior.

These types interact with order book dynamics differently. For instance, placing a large IOC buy order in a shallow market may result in multiple price levels being hit, leading to average fill prices. FOK orders in the same scenario would fail entirely. Post Only orders in a fast-moving market may never fill if prices move past the limit too quickly.

Traders should also consider leverage, margin mode, and position mode when using these execution types, as they influence liquidation risks and order handling during volatility.

Common Mistakes and How to Avoid Them

New users often misunderstand how execution types behave under real market conditions. Common pitfalls include:

• Assuming Post Only orders will always be placed; they may be rejected if they would immediately match.
• Using FOK without checking order book depth, leading to repeated order rejections.
• Expecting IOC to guarantee a specific price, when in reality, it may fill at multiple price points.

To prevent these issues:

• Use the depth chart to assess available liquidity before placing FOK or large IOC orders.
• Set limit prices conservatively when using Post Only to avoid rejection.
• Monitor recent trades and spread to estimate execution likelihood.

Bybit provides real-time feedback on order status, so watching the notification panel helps identify why an order was filled, cancelled, or rejected.

Frequently Asked Questions

Can I use Market orders with Post Only execution?

No, Post Only is only available for Limit orders. Market orders always execute against existing liquidity, making them taker orders by nature, which contradicts the Post Only principle.

What happens if my Post Only order would immediately match?

Bybit will either cancel the order or adjust its price to prevent immediate execution, depending on your settings. This ensures the order remains on the book as a maker.

Is there a fee difference between IOC and FOK orders?

Both IOC and FOK are typically taker orders and incur taker fees. The fee structure does not differ between these execution types; it depends on whether the order removes liquidity.

Can I change the execution type after placing an order?

No, execution types are fixed at the time of order submission. To modify it, you must cancel the original order and place a new one with the desired execution type.