To protect users from potential price volatility and risks associated with new spot trading pairs, OKX employs different opening mechanisms based on the type of trading pair and prevailing market conditions. The specific method used—whether a call auction or early order placement—is detailed in the announcement for each newly listed token.
For entirely new tokens that require price discovery, OKX typically uses a call auction. For tokens that already have a reliable index price available and do not require price discovery, early order placement is usually adopted. The final decision on the opening mechanism is made based on real-time market conditions.
What Is a Call Auction?
An OKX call auction is a process that occurs before a new trading pair officially begins continuous trading. During this period, users can freely submit buy and sell orders at their preferred price levels. The trading system then processes all these orders according to specific call auction rules to compute a projected opening price.
Which Tokens Use the Call Auction Mechanism?
The call auction mechanism is applied to newly listed spot trading pairs.
How Long Does the Call Auction Last?
The duration varies depending on the token and market liquidity. Typically, it lasts for at least 10 minutes.
What Order Types Are Supported During the Call Auction?
Only limit orders are supported during the call auction phase.
How Are Fees Charged for Trades Matched in the Call Auction?
For orders that are matched and executed at the end of the call auction, the system charges a transaction fee based on the Taker fee standard.
How Is the Projected Opening Price Determined?
The projected opening price is calculated based on three simultaneous conditions:
- This price must achieve the highest possible trading volume.
- All buy orders placed above this projected price and all sell orders placed below it must be executable.
- For orders exactly at the projected price, either all buy orders or all sell orders must be fully executable.
What Are the Specific Rules of the Call Auction?
- Call Auction Phase (minimum 10 minutes): You can place, cancel, or modify limit orders until the final five minutes. During the last five minutes, you may only place new orders; cancellation or modification is not permitted.
- Live Trading Phase: The final opening price, calculated from the price discovery during the call auction, becomes the official opening price. Orders matched during the call auction are sent to the matching engine once live trading starts and are usually executed within 1 to 15 seconds. Any unmatched orders from the call auction remain on the order book and are executed according to standard order book trading rules.
Who Can Participate in the Call Auction?
All OKX users are eligible to participate in call auctions.
Are There Order Quantity Limits During the Call Auction?
Yes, there are limits on the total order quantity a user can place during the call auction. For specific details, please refer to the relevant token listing announcement.
Is API Trading Supported During the Call Auction?
Yes. You can use the API to place orders during the call auction, just as with other products. Market and order book data are also available via REST API and WebSocket push. For comprehensive API information, 👉 explore the full API documentation.
What Trading Information Is Provided During the Call Auction?
- Projected Opening Price: The estimated price for the trading pair.
- Matched Order Volume: The quantity of the token successfully matched during the auction.
- Unmatched Order Volume: The quantity of the token that was not matched.
Why Might the Opening Price on the Chart Differ from the Projected Price?
To provide additional trading context, after the call auction concludes, OKX uses the opening price provided by the token project team at the start of spot trading as the initial price on the trading chart. This project-provided price is typically based on the project's own valuation and is for reference only. It is not determined by the call auction mechanism and does not affect the price at which your orders are executed.
What Is Early Order Placement?
OKX's early order placement is a process that allows users to place buy and sell orders for a new trading pair before it officially begins continuous trading. The primary goal is to provide sufficient liquidity before the official opening to ensure stable market trading. During this phase, buyers and sellers can place limit orders within a range defined by an index price. Buy orders must be placed below a maximum buy price (index price (1+J%)), and sell orders must be placed above a minimum sell price (index price (1-J%)). At the end of the early order period, the system uses the index price as a benchmark to cancel certain orders. Specifically, buy orders with a price lower than or equal to the index price and sell orders with a price higher than or equal to the index price are canceled. Unlike the call auction, no trades are executed at the end of this phase; orders that are not canceled remain on the book and enter the continuous trading session.
Which Tokens Use the Early Order Placement Mechanism?
Early order placement is used for newly listed spot trading pairs that have a reliable index price available.
How Long Does the Early Order Placement Last?
The duration varies by token and market liquidity. It typically lasts for at least 30 minutes.
What Order Types Are Supported During Early Order Placement?
Only limit orders are supported during the early order placement phase.
How Are Fees Charged for Early Order Placement?
Since no trades are executed at the end of the early order placement phase, no transaction fees are incurred.
What Are the Specific Rules of Early Order Placement?
- Early Order Placement Phase: Users can place, cancel, or modify limit orders.
- Live Trading Phase: The system cancels orders using the index price at the end of the early order period. Buy orders with a price lower than or equal to the index price and sell orders with a price higher than or equal to the index price are canceled. No execution occurs at this stage. Orders that are not canceled remain on the order book and enter continuous trading, where they are executed according to standard order book rules.
Who Can Participate in Early Order Placement?
All OKX users are eligible to participate in early order placement.
Are There Price Limits for Orders During Early Order Placement?
Yes, price limits based on the index price are in effect. Buy orders must be below the maximum buy price (index price (1+J%)), and sell orders must be above the minimum sell price (index price (1-J%)). For example, if a token's index price is 1 and the limit range (J) is 2%:
- Maximum Buy Price: 1.02
- Minimum Sell Price: 0.98
Can the Best Bid Price Be Higher Than the Best Ask Price During This Phase?
Yes. Because the index price and the resulting price limits can change during the early order period, it is possible for the best bid price to be higher than the best ask price. However, the system will not execute these orders against each other. All orders are displayed normally on the order book.
Is API Trading Supported During Early Order Placement?
Yes. You can use the API to place orders during early order placement, just as with other products. Market and order book data are also available via REST API and WebSocket push. For comprehensive API information, 👉 access the detailed API guide.
What Trading Information Is Provided During Early Order Placement?
- Index Price: The current index price for the trading pair.
- Maximum Buy Price: The highest price the system will currently accept for a buy order.
- Minimum Sell Price: The lowest price the system will currently accept for a sell order.
Where Can I Find the Index Price at the End of the Early Order Phase?
The index price at the conclusion of the early order placement phase is displayed as the starting point on the trading pair's candlestick chart.
OKX is committed to providing users with an optimal trading experience. We continuously monitor market activity and refine our early order placement model, with updates published in our documentation. Please check this documentation regularly for the latest information.
Frequently Asked Questions
What is the main difference between a call auction and early order placement?
The key difference lies in price discovery and trade execution. A call auction is used for new tokens without an established price to discover a market-driven opening price through order matching. Early order placement is for tokens with an existing index price and focuses on building liquidity without an initial trade execution; orders are simply placed on the book for continuous trading.
Can I cancel my order during the call auction?
Yes, but only until the final five minutes of the auction phase. Once the last five minutes begin, you can only place new orders; cancellations or modifications are not permitted.
Why would my order be canceled at the end of the early order placement phase?
Your order will be canceled if it is a buy order priced at or below the final index price, or a sell order priced at or above it. This is a mechanism to prevent executions at potentially unfavorable prices relative to the established market index at the time live trading begins.
Is there a risk of large price gaps when using these mechanisms?
These mechanisms are designed specifically to mitigate the risk of extreme volatility and price gaps at the opening of a new market. The call auction aims to find a consensus price, while early order placement helps build a liquid order book beforehand.
How can I stay informed about which mechanism will be used for a new listing?
OKX announces the listing method for each new token in its official listing announcements. It is crucial to read these announcements carefully before participating.
Where can I learn more about the specific API endpoints for these features?
All relevant API methods for interacting with call auctions and early order placement are detailed in the official OKX API documentation. 👉 Discover the API endpoints for these features.