The key difference in OKX's new token listing order mechanism is whether the token uses a call auction or a pre-open session. In a call auction, you cannot cancel orders during the last five minutes. In a pre-open session, you can cancel and modify orders at any time. Both only support limit orders and neither executes trades immediately, but the rules for changing your mind before the close are completely different.
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Check the Announcement First: Which Mechanism Does This Token Use
Before every new token goes live, OKX publishes an announcement. The announcement will state whether the trading pair uses a "call auction" or a "pre-open" session, along with the specific time periods.
These two mechanisms are never used at the same time for the same new token. You can tell them apart by looking at the keywords in the announcement title or body:
Call Auction: Usually used for brand-new tokens that need price discovery. The announcement will mention a "call auction period."
Pre-Open: Usually used for new tokens that already have an index price as a reference. The announcement will say "Pre-open" or "pre-open session."
If neither term appears in the announcement, the token may go live directly without a pre-collection phase for orders.
Call Auction: No Cancellations in the Last Five Minutes
The core rule of a call auction is "place orders freely first, then lock orders for matching at the end." The whole process is divided into two stages:
Stage 1 (from the start until 5 minutes before the end): You can freely submit limit buy and sell orders, and you can cancel or modify them at any time. The system collects all orders in real time but does not execute any trades. The screen shows an "estimated opening price" that changes as orders come in.
Stage 2 (the last 5 minutes): You can still submit new limit orders, but you can no longer cancel or modify any existing orders. This is the most important operational restriction in a call auction.
After the auction ends, the system calculates a single opening price, and all matched orders during the call auction are filled at this price. The opening price is determined by the principle of "maximum volume": at the price that satisfies this condition, all buy orders above the opening price and all sell orders below the opening price are fully filled.
Call auctions only support limit orders; market orders will be rejected. Orders filled during the call auction phase are charged at the Taker fee rate.
Unfilled orders from the call auction do not disappear. They remain in the order book and enter the continuous trading phase, where they continue waiting to be filled.
Pre-Open: You Can Cancel Anytime, but Prices Have Hard Limits
The fundamental difference between pre-open and call auction is this: during the pre-open session, orders are not filled, but you can place, cancel, and modify orders at any time. There is no lock-up period at all.
Price constraints in pre-open are stricter than in call auction. Your orders must be placed around an index price or reference price:
Buy orders cannot be priced higher than Index Price × (1 + J%)
Sell orders cannot be priced lower than Index Price × (1 - J%)
The J parameter is set by OKX based on market conditions and may differ between trading pairs.
When the pre-open session ends, orders whose prices do not meet the final reference price will be canceled. Specifically, buy orders priced above the reference price and sell orders priced below the reference price will be removed by the system. Orders that meet the price requirements remain in the order book and enter formal trading.
Pre-open sessions also only support limit orders, and no fees are charged because no trades actually occur.
The First 5 Minutes After Opening: Two Extra Restrictions
Whether a token goes through call auction or pre-open, there are two hard restrictions during the first 5 minutes after formal continuous trading begins:
Restriction 1: No market orders. During these 5 minutes, market order submissions will fail directly. You can only place limit orders.
Restriction 2: Maximum limit order size of 10,000 USD. If you place a limit order exceeding 10,000 USD, it will be rejected. This limit is automatically lifted after 5 minutes.
Also, if you placed orders during the call auction phase, they remain valid after continuous trading begins and will participate in matching according to normal order book rules.
Which Number Should You Look At
When placing orders, the screen shows several prices. You need to tell them apart:
Estimated opening price: A reference price calculated in real time during the call auction phase. It changes as orders come in. It does not represent the final fill price. After the call auction ends, a formal opening price will be recalculated.
The "opening price" on the chart: The first price shown on the trading chart after the call auction ends. It may be a reference price provided by the project team, usually based on the project's valuation. This price is for reference only. It is not determined by the call auction mechanism, and it does not affect the actual fill price of your orders.
The final price at which your order is filled depends on the opening price calculated at the end of the call auction, as well as your position in the order book.
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References
- OKX·Explanation of Call Auction and Early Order Placement, page published or updated: 2025-12-26; verified: 2026-10-04.
- OKX·OKX Listing Mechanism, page published or updated: 2026-08-05; verified: 2026-10-04.
- OKX·Pre-Market Trading Product Rules, page published or updated: 2026-07-14; verified: 2026-10-04.
- OKX·Announcement on Listing BASED for Spot Trading, page published or updated: 2026-03-29; verified: 2026-10-04.
- OKX·Announcement on Listing AEON/USDT (Aeon) for Spot Trading, page published or updated: 2026-07-26; verified: 2026-10-04.
- OKX·OKX to list ASTER (Aster) for spot trading, page published or updated: 2025-10-16; verified: 2026-10-04.
- OKX·Announcement on Supporting the MOVE/USDC Trading Pair, page published or updated: 2024-12-08; verified: 2026-10-04.
