Why Was My Limit Order Not Filled or Not Filled Immediately? – VOOX

What is a Limit Order?

A limit order does not guarantee immediate execution. Reasons for non-execution may involve price, quantity, trading rules, and market volatility. Understanding these factors can help optimize your order placement strategy.

A limit order is an order placed on the order book at a specific price. It will only be executed when the market price reaches your limit price (or a better one). You can use limit orders to buy assets below the market price or sell them above the market price.

Understanding the Order Book

The order book is a real-time list of buy and sell orders in the market.

Buy Orders (Bid): Shown in green, these represent orders from buyers willing to pay no more than a certain price.
Sell Orders (Ask): Shown in red, these represent orders from sellers willing to accept no less than a certain price.

The point where the highest bid and the lowest ask meet is called the market price.

When Will My Limit Order Be Filled?

A limit buy order will only be filled under the following three conditions:

The market price has reached your limit price or lower (a better price)
Let’s take a limit buy order as an example. When the current market price is $2,400 (A) and the limit buy order is placed at $1,500 (C), the order will not be executed until the price drops to $1,500 (C) or below (if executed below $1,500, it means you got a better deal).
Sufficient liquidity is available in the market to fulfill the order
When the current market price is $1,500 (C), but there are no corresponding sell orders, the buy order will not be executed. However, if liquidity only satisfies part of the order, partial execution may occur.
There is enough time for execution
During periods of high volatility, even if the market price reaches your limit price, your order may not have enough time to reach the order book and get executed at the matching price.

Common Reasons for Non-Execution

Price not reached: The set price is far from the current market price.
Insufficient counterparty volume: Only partial execution occurs.
Market volatility: The price skipped past your order too quickly.
Time condition restrictions: IOC/FOK settings may lead to order cancellation.
Post-Only: Orders meant to avoid immediate execution may be canceled by the system.
Non-compliant quantity or precision: The order does not meet the minimum quantity or price precision requirements.
Insufficient account balance or risk control restrictions: These may cause order failure or partial execution.

FAQs

Q: Does it indicate a system error if my limit order remains unfilled?

A: In most cases, it is due to the price not being reached or insufficient liquidity.

Q: What can I do to ensure immediate execution?

A: Use a market order or a limit order with Immediate-Or-Cancel (IOC).

Q: Why wasn’t my limit order filled immediately?

A: It’s because the market price hasn’t reached your specified price. The order remains on the order book waiting for execution.

Q: Why was my limit order only partially filled?

A: The number of orders from counterparties at that price level is limited, so only a portion may be matched. The remainder will stay on the order book.

Q: How can I resolve this?

To execute quickly → Use a market order.
To wait for a better price → Keep the limit order active on the order book.

📌 Summary and Risk Reminder

The market changes rapidly, and order execution is subject to liquidity and trading rules.
Understanding the order book, order types, and matching mechanisms can help you plan your trading strategies more effectively.
Please set order parameters reasonably according to your risk tolerance to avoid unnecessary losses caused by price gaps or insufficient market depth.