What is the one-hour call auction before a new OKX listing opens?

In its September 2026 CP/USDT listing announcement, OKX sets out the order for a new coin: deposits open, a 1-hour call auction runs, spot trading opens, and then withdrawals open. Market orders submitted in the first 5 minutes after the call auction ends are rejected, and for the first few minutes of trading, buy orders also have a maximum price. The cap on buy orders and the cancellation limit during the auction come from the 2025 PUMP announcement and aren't in every announcement.

In China's A-share market, “call auction” is the matching session before the open on each trading day. The call auction here is one step in listing a new coin, and its timing and order limits are written into each listing announcement, so stock-market sessions and rules don't apply to it.

01A new listing runs in four steps: deposits, call auction, open, withdrawals

Every listing announcement starts with a listing timeline. Here are the schedules from two announcements, with all times in UTC:

Both call auctions last 1 hour, and spot trading opens as soon as the auction ends. The differences are at either end: CP deposits opened more than a day ahead, while PUMP deposits opened earlier the same day; from the open to withdrawals, CP took 2 hours and PUMP 4. So don't estimate the next coin's times from the last one; check the listing timeline in that coin's own announcement every time.

To buy in the call auction, you need USDT in your OKX account before the auction starts. If you hold the new coin elsewhere and want to move it in on-chain to sell, the deposit opening time is the earliest you can transfer it. Coins bought after the open, in turn, can only be withdrawn once withdrawals open. For choosing the network and address, see OKX Deposit & Withdraw Crypto: Address, Fees, Timing, Limits.

02What orders can you place during the one-hour call auction?

The PUMP announcement explains the call auction in one section: before a new trading pair officially begins trading, you can submit buy and sell orders at the prices you want, within set trading parameters; the trading system processes all submissions according to call auction rules and calculates an indicative opening price from them.

The same section adds two limits:

• “the total value of each user’s buy orders during a call auction must not exceed 50,000 USD”;
• “during the last 5 minutes before the call auction ends, users can still place orders but cannot cancel or modify orders”.

Both come from the 2025 PUMP announcement. The September 2026 CP/USDT announcement doesn't contain either sentence; its spot market opening risk control rules only cover market orders and price limits after the open. Not finding them there doesn't mean you can cancel freely this time, nor that the cap has been dropped. For the coin you plan to trade, read what its own announcement says in the call auction section.

When you prepare, you can work to the strictest version: settle your price and quantity before the last 5 minutes of the auction, and treat any order placed in those last 5 minutes as one you can't take back.

03Market orders are rejected for 5 minutes after the call auction ends

The spot market opening risk control rules in the CP/USDT announcement say that market orders are not supported for the first 5 minutes after the call auction ends, and that market orders submitted in that window are rejected.

The 5 minutes start when the call auction completes, which is the moment spot trading opens. To get filled in that window, you have to place a limit order and set the price yourself. If you've never placed a limit order and a market order, practise one of each on a demo account first.

The CP/USDT announcement lists only that market-order rule. When PUMP listed, the same 5 minutes came with more restrictions, which OKX said were there to protect investors from market volatility during new coin listings:

• Market orders were not allowed;
• The maximum amount per limit order was $10,000;
• The maximum net position per user was $10,000;
• These restrictions were lifted 5 minutes after trading started.

04Price limit rules cap buy prices in the first minutes after the open

Once trading opens, order prices also have to pass a price limit. When a newly listed coin has no index price or no stable one, the platform uses closing price-based limit rules; once the pair has a stable index price, it switches to index-based limit rules.

Under the closing price rules, the buy cap in the first minute is tied straight to the call auction's execution price; after that it follows the previous minute's closing price, minute by minute, and sell orders have no floor. So if you want to chase the price in the first minute, the highest you can bid is (1 + H) times the auction's execution price.

H, N, X, Y and Z are all parameters OKX can change: it may adjust them, or switch the limit price calculation method, based on market conditions and without prior notice. The real-time rules are on OKX's /trade-market/info/spot page; before you place an order, rely on that page and the announcement for the coin you're trading.

05The fine print of each call auction is in that listing's announcement