Introduction
To protect users from the price volatility associated with opening a new spot order book, OKX may employ different mechanisms depending on the type of token being listed. For newly launched crypto tokens that require price discovery, OKX may use a call auction mechanism. For crypto tokens with an established index price that do not require price discovery, OKX may implement a pre-open mechanism. The specific mechanism applied depends on actual market conditions.
What Is the OKX Call Auction?
The OKX Call Auction allows you to submit buy and sell orders at your desired prices for free before a new trading pair officially begins live trading. The trading system processes all submissions according to the call auction rules and calculates an indicative opening price based on these orders.
Supported Cryptocurrencies for Call Auction
Call auctions are used for newly listed trading pairs.
Duration of the Call Auction
The duration of the call auction depends on the specific cryptocurrency and market liquidity. Typically, the call auction lasts for at least 10 minutes.
Order Types Supported During Call Auction
Only limit orders are supported during the call auction period.
Fee Calculation During Call Auction
At the end of the call auction, the system charges a taker fee for orders that were matched during this period.
How the Indicative Opening Price Is Determined
The indicative opening price must satisfy the following three conditions:
- It must generate the highest trading volume.
- All buy orders above the indicative opening price, or all sell orders below the indicative opening price, must be fully executed at the opening price.
- The taker or maker of the orders at the indicative opening price must be fully executed.
Rules for the Call Auction
- Call Auction Phase (lasts at least 10 minutes): You can place, cancel, or modify limit orders until the last five minutes. During the final five minutes of the call auction, you can only place orders; cancellation or modification is not allowed.
- Live Trading Phase: The final indicative opening price, calculated based on price discovery during the call auction, is used as the official opening price. Once live trading begins, matched orders from the call auction phase are entered into the matching engine and usually executed within 1 to 15 seconds. Unmatched orders from the call auction remain in the order book and are executed based on the order book trading rules.
Who Can Participate in the Call Auction?
All OKX users can participate in the call auction.
Order Limits During Call Auction
Yes, there is a limit on the total order size that users can place during the call auction. For more details, please refer to the respective listing announcement.
API Support for Call Auction
Yes. Similar to other trading products, you can place orders via API during the call auction. You can also access market data and order book depth through the REST API and WebSocket feed. For more information, you can explore the API documentation.
Information Provided to Users During Call Auction
- Indicative opening price: The estimated price for the trading pair.
- Matched order volume: The amount of cryptocurrency successfully matched during the call auction.
- Unmatched order volume: The amount of cryptocurrency not matched during the call auction.
Why the Indicative Price Differs from the Chart Opening Price
To provide additional trading information, OKX displays the project team's opening price at the start of continuous trading as the initial price on the trading chart after the call auction ends. The project team's opening price is usually provided by the token project team based on project valuation. This price is for informational purposes only, is not determined by the call auction mechanism, and does not affect the execution prices of your orders.
What Is the OKX Pre-Open Mechanism?
The OKX Pre-Open mechanism allows you to place buy and sell orders at your desired prices according to specific trading parameters before official market trading begins. The main purpose of the pre-open session is to provide liquidity to the trading pair, enhancing market continuity and stability.
During the pre-open session, buyers and sellers place limit orders around the index price, constrained by the index price limit. Buy orders must be lower than the index price limit (1 + X%); sell orders must be higher than the index price limit (1 - X%). At the end of the pre-open session, the final index price is used to cancel invalid orders. Sell orders below the index price and buy orders above the index price are invalid and will be canceled. Orders are not executed during the pre-open session. Non-canceled orders are retained in the order book for continuous trading.
Supported Cryptocurrencies for Pre-Open
Pre-open is used for newly listed spot trading pairs that have an index price.
Duration of the Pre-Open Session
The session duration depends on the specific cryptocurrency and market liquidity. Typically, the pre-open session lasts at least 30 minutes.
Order Types Supported During Pre-Open
Only limit orders are supported during the pre-open session.
Fee Calculation During Pre-Open
No fees are charged during or after the pre-open session since no orders are matched or executed.
Rules for the Pre-Open Session
- Pre-Open Session (typically lasts at least 30 minutes): You can place, cancel, or modify limit orders.
- Live Trading Phase: The final index price at the end of the pre-open session is used to cancel invalid orders. Sell orders below the index price and buy orders above the index price are canceled. Non-canceled orders remain in the order book and are executed based on the order book trading rules.
Who Can Participate in the Pre-Open Session?
All OKX users can participate in the pre-open session.
Price Limits for Orders During Pre-Open
Yes, a price limit based on the index price is applied. Bid orders must be lower than the index price + X%. Ask orders must be higher than the index price - X%. The X% value acts as a buffer around the index price, which may change during the pre-open session.
Example: The index price of Token 1 is 1.00, and the X% price limit is set to 2%. This allows traders to have a buffer in their bids and asks as the index price moves.
- Maximum bid price: 1.02
- Minimum ask price: 0.98
Can the Best Bid Price Be Higher Than the Best Ask Price During Pre-Open?
Yes. Since the price limit is based on the index price and the index price may fluctuate during the pre-open session, it is possible for the best bid price to be higher than the best ask price. The bid and ask order prices are displayed in the order book.
API Support for Pre-Open
Yes. Similar to other trading products, you can place orders via API during the pre-open session. You can also access market data and order book depth through the REST API and WebSocket feed. For more information, you can access detailed API guides.
Information Provided to Users During Pre-Open
- Current index price: The current index price for the crypto trading pair.
- Maximum bid price: The highest price of bid orders that can be accepted.
- Minimum ask price: The lowest price of ask orders that can be accepted.
Where to Find the Final Index Price Used for Order Cancellation
OKX displays the final index price used for canceling orders and as the starting price for the K-line chart.
OKX is committed to providing users with a better trading experience. The platform continuously monitors market activities, improves the pre-open mechanism, and updates this document accordingly. Please check back for updates.
Frequently Asked Questions
What is the main difference between call auction and pre-open?
The call auction is used for new tokens requiring price discovery, determining an opening price via order matching. Pre-open is for tokens with an existing index price, focusing on liquidity provision without execution during the session.
Can I cancel my orders during the call auction?
You can cancel or modify limit orders until the last five minutes of the call auction. In the final five minutes, only order placement is allowed.
How does OKX ensure fairness in the call auction process?
OKX uses a transparent set of rules to calculate the indicative opening price based on the highest trading volume and full order execution at that price, ensuring a fair market-driven outcome.
Why are there price limits in the pre-open session?
Price limits based on the index price prevent extreme order placements, maintain market stability, and provide a buffer for index price fluctuations during the session.
Is there a risk of orders being canceled in the pre-open mechanism?
Yes, orders that are invalid (e.g., sell orders below the final index price or buy orders above it) are canceled at the end of the pre-open session to ensure orderly market opening.
Where can I learn more about specific parameters for upcoming listings?
For detailed information on order limits, session duration, and index price sources, refer to the official OKX listing announcements and documentation.