To protect users from price volatility when a new spot order book opens, OKX employs different mechanisms based on the types of tokens being listed. For newly listed cryptocurrency tokens that require price discovery, OKX may use the call auction mechanism. For tokens with an established index price that do not require price discovery, the pre-opening mechanism may be implemented. The exact mechanism depends on real-time market conditions.
What is the OKX Call Auction?
The OKX call auction allows you to freely submit buy and sell orders at your desired prices before the new trading pair officially opens. The trading system processes all submitted orders according to the call auction rules and calculates an indicative opening price based on these orders.
Which Cryptocurrencies Use Call Auction?
Call auctions are typically used for newly listed trading pairs.
How Long Does the Call Auction Last?
The duration varies based on the specific cryptocurrency and market liquidity. Generally, a call auction lasts at least 10 minutes.
Supported Order Types During Call Auction
Only limit orders are supported during the call auction phase.
Fee Structure During Call Auction
At the end of the call auction, the system charges a taker fee for all orders executed during this period.
Determining the Indicative Opening Price
The indicative opening price must meet three conditions:
- It must generate the maximum trading volume.
- All buy orders above the indicative opening price or sell orders below it must be fully executed at this price.
- Taker or maker orders at the indicative opening price must be completely filled.
Call Auction Rules
- Call Auction Phase (minimum 10 minutes): You can place, cancel, or modify limit orders until the last five minutes. During the final five minutes, you can only place orders—cancellations or modifications are not allowed.
- Live Trading Phase: The calculated indicative opening price becomes the official opening price. Matching orders from the call auction phase enter the matching engine and execute within 1 to 15 seconds. Non-matching orders remain in the order book and execute according to standard trading rules.
Who Can Participate?
All OKX users can participate in the call auction.
Are There Order Limits?
Yes, there are limits on the total order volume users can place during the call auction. Check specific listing announcements for details.
API Support for Call Auction
Yes. Similar to other trading products, you can place orders during the call auction via API. Market data and order book depth are accessible through REST API and WebSocket feeds. For more information, 👉 explore the API documentation.
Information Provided During Call Auction
- Indicative Opening Price: Estimated price for the trading pair.
- Matched Order Volume: Amount of cryptocurrency successfully matched during the auction.
- Unmatched Order Volume: Amount of cryptocurrency not matched during the auction.
Why Indicative Price Differs From Chart Opening Price
To provide additional trading information, after the call auction ends, OKX may display the project team's opening price at the start of continuous trading as the initial price on the trading chart. This price, provided by the token project team, is based on project valuation and is for informational purposes only. It is not determined by the call auction mechanism and does not affect order execution prices.
What is the OKX Pre-Opening Session?
The OKX pre-opening session allows you to submit buy and sell orders at desired prices within certain trading parameters before official market trading begins. The primary goal is to provide liquidity for the trading pair, enhancing market continuity and stability. During pre-opening, buyers and sellers submit limit orders around the index price, constrained by index price limits. Buy orders must be below the index price(1 + X%); sell orders must be above the index price(1 - X%). At the end of the session, the final index price cancels invalid orders. Sell orders below the index price and buy orders above it are considered invalid and canceled. No orders execute during pre-opening; non-canceled orders remain in the order book for trading. Once live trading begins, these orders stay in the book.
Which Cryptocurrencies Use Pre-Opening?
Pre-opening is used for newly listed spot trading pairs with existing index prices.
Duration of Pre-Opening Session
The duration depends on the specific cryptocurrency and market liquidity. Typically, pre-opening lasts at least 30 minutes.
Supported Order Types During Pre-Opening
Only limit orders are supported.
Fee Structure During Pre-Opening
No fees are charged during or after pre-opening, as no orders are matched or executed.
Pre-Opening Rules
- Pre-Opening Session (usually at least 30 minutes): Users can place, cancel, or modify limit orders.
- Live Trading Phase: The final index price at the session's end cancels invalid orders. Sell orders below the index price and buy orders above it are canceled. Non-canceled orders remain in the order book and execute per standard trading rules.
Who Can Participate?
All OKX users can participate in pre-opening.
Are There Price Limits for Orders?
Yes, price limits based on the index price apply. Bid orders must be below index price + X%. Ask orders must be above index price - X%. The X% margin accommodates index price fluctuations during pre-opening.
For example, if the token's index price is 1 and X% is set to 2%:
- Maximum bid price: 1.02
- Minimum ask price: 0.98
Can Best Bid Price Exceed Best Ask Price During Pre-Opening?
Yes. Because price limits are based on the moving index price, the best bid price may exceed the best ask price during pre-opening. Bid and ask order prices are displayed in the order book.
API Support for Pre-Opening
Yes. You can place orders during pre-opening via API. Market data and order book depth are accessible through REST API and WebSocket feeds. For details, 👉 access comprehensive API guides.
Information Provided During Pre-Opening
- Current Index Price: Real-time index price for the cryptocurrency trading pair.
- Maximum Bid Price: Highest acceptable bid order price.
- Minimum Ask Price: Lowest acceptable ask order price.
Where to Find the Final Index Price for Order Cancellation
OKX displays the final index price used to cancel orders. This price also serves as the initial price for the K-line chart.
OKX is committed to providing a better trading experience for users. We closely monitor market activities, continuously improve the pre-opening mechanism, and update this document timely. Revisit this page for the latest updates.
Frequently Asked Questions
What is the main difference between call auction and pre-opening?
Call auction is for new tokens requiring price discovery, while pre-opening is for tokens with an established index price. Call auction determines an opening price through order matching, whereas pre-opening focuses on liquidity without immediate execution.
Can I cancel orders during the call auction?
Yes, but only until the last five minutes. During the final five minutes, orders cannot be canceled or modified.
How does OKX ensure fairness during these sessions?
Both mechanisms use transparent, rule-based processes. The call auction calculates the opening price to maximize trade volume, and pre-opening applies clear index-based price limits to maintain market stability.
Are there risks associated with participating in call auctions?
Yes, due to price volatility in new listings. The indicative price may change, and orders might execute at unexpected levels. Users should carefully consider their order prices.
What happens if my pre-opening order is canceled?
Canceled orders are removed from the order book. You can place new orders once live trading begins, based on the final index price and market conditions.
How often does OKX update these mechanisms?
OKX continuously monitors market feedback and may adjust parameters like duration or price limits to improve user experience. Changes are announced via official channels.