Introduction
To protect users from price volatility associated with opening a new spot order book, OKX employs different mechanisms depending on the types of tokens listed:
- Call Auction: Used for newly listed cryptocurrency tokens requiring price discovery.
- Pre-Opening: Applied to tokens with established index prices that don’t require price discovery.
The exact mechanism depends on real-time market conditions.
Section 1: OKX Call Auction
1. What Is OKX’s Call Auction?
The call auction allows users to freely submit buy/sell orders at desired prices before official trading begins. The system calculates an indicative opening price based on these submissions.
2. Which Cryptocurrencies Use Call Auctions?
Newly listed trading pairs.
3. Duration of Call Auction
Typically ≥10 minutes, varying by market liquidity.
4. Supported Order Types
Only limit orders are accepted.
5. Fee Structure
A taker fee applies to orders executed during the auction.
6. How Is the Indicative Opening Price Determined?
The price must:
- Maximize trading volume.
- Fully execute all eligible buy/sell orders.
- Ensure complete execution of taker/maker orders at the opening price.
7. Call Auction Rules
- Auction Phase (≥10 min): Submit/cancel/modify limit orders until the last 5 minutes (modifications locked thereafter).
- Live Trading: Orders from the auction phase enter the matching engine and execute within 1–15 seconds. Unmatched orders remain in the order book.
👉 Learn how call auctions enhance price fairness
8. Eligibility
All OKX users can participate.
9. Order Limits
Yes, volume limits apply. Check specific listing announcements.
10. API Support
Yes. Use REST API or WebSocket for order submissions and market data.
11. User Information During Auction
- Indicative opening price.
- Matched/unmatched order volumes.
12. Why Does the Indicative Price Differ from the Chart’s Opening Price?
The chart displays the project team’s suggested opening price (for reference only), which doesn’t affect actual trade execution.
Section 2: Pre-Opening Mechanism
1. What Is Pre-Opening?
Users submit limit orders within index price ±X% before live trading begins. Invalid orders are canceled post-session.
2. Applicable Cryptocurrencies
Newly listed spot pairs with established index prices.
3. Duration
Typically ≥30 minutes.
4. Supported Orders
Limit orders only.
5. Fees
None (no orders execute during pre-opening).
6. Rules
- Pre-Opening Phase: Submit/cancel/modify orders freely.
- Live Trading: Invalid orders (outside index price ±X%) are canceled; others remain in the order book.
7. Eligibility
All OKX users.
8. Price Limits
Example: If index price = 1 and X% = 2%, bids ≤1.02 and asks ≥0.98 are allowed.
9. Can the Best Bid Exceed the Best Ask?
Yes, due to index price fluctuations.
10. API Support
Yes. Access market data via REST API or WebSocket.
👉 Explore OKX’s trading API documentation
11. User Information During Pre-Opening
- Current index price.
- Max bid/min ask prices.
12. Final Index Price Visibility
Displayed post-session and used as the K-line chart’s initial price.
FAQs
Q1: How does OKX ensure fairness in call auctions?
A1: By maximizing volume and executing all eligible orders at a single price.
Q2: Can I cancel orders during the last 5 minutes of a call auction?
A2: No—modifications are locked.
Q3: Are pre-opening orders executable?
A3: No, they’re validated only after the session ends.
Q4: What happens to invalid pre-opening orders?
A4: Canceled automatically.
Q5: How often does OKX update these mechanisms?
A5: OKX continuously optimizes based on market feedback.
Q6: Where can I find historical auction data?
A6: Via OKX’s API or market data archives.