MEXC Futures Post-Only FAQs
1. What is a post-only order?
A "post-only" order is a type of order designed to ensure you always act as a maker. It guarantees that your order will not be executed immediately against the market. If your submitted order instantly matches with an existing one, the system will automatically cancel it.
In Futures trading, a maker is a trader who places a limit order on the order book and waits for others to fill it, thereby adding liquidity to the market. In contrast, a taker is a trader who immediately executes against existing limit or market orders, thus consuming market liquidity.
2. What are the advantages of post-only?
The core advantage of using post-only is the fee discount. In MEXC Futures trading, the fee rate for maker orders is significantly lower than for taker orders. This can substantially reduce trading costs for users who trade frequently.
3. What are the disadvantages of post-only?
The main disadvantage of post-only is that immediate execution is not guaranteed. Since these orders are placed on the book to wait rather than aggressively taking liquidity, your order might miss trading opportunities if the market moves quickly and the price never reaches your level. Additionally, post-only may not be the best choice when you need to close a position urgently.
4. Why was my post-only order automatically canceled?
Orders are typically auto-canceled for the following reasons:
If your buy price is set higher than the current best ask, or your sell price is lower than the current best bid, the order will be executed immediately, making you a taker. To adhere to the post-only principle, the system automatically cancels such orders. For example, if the current BTC market price is 40,000 USDT and you place a buy order at 41,000 USDT, the order will be immediately canceled to ensure you remain a maker.
Another scenario is when the price meets the criteria at the moment of submission, but significant market volatility occurs before the order reaches the matching engine, causing it to become a taker order. In this case, it will also be canceled.
5. Does using post-only guarantee a maker fee rate 100% of the time?
In principle, yes, but it does not guarantee execution. The purpose of post-only is to prevent your order from executing as a taker. However, this is not the same as guaranteeing that your order will be filled. If the limit price you set deviates too much from the current market price, your order may remain on the order book for an extended period without executing, posing a risk of missing trading opportunities.
6. Can post-only be used to close a position?
Yes, but it should be used with caution. Using post-only to close a position still follows the rule of no immediate execution. During rapid market volatility, if the order can't get filled at your desired limit price, your position may face increased risk. Therefore, in scenarios requiring urgent stop-losses, using the post-only function is not recommended.
7. How to set up a post-only order on MEXC
Web: Navigate to the Futures trading page, select Post-Only, enter the Price and Quantity, configure TP/SL, and then click Open Long or Open Short.
App: Navigate to the Futures trading page, select Post-Only, enter the Price and Quantity, configure TP/SL, and then tap Open Long or Open Short.
8. What are some common mistakes when using post-only?
A frequent error is using post-only when speed is the priority. This order type is designed for traders willing to wait for a fill in exchange for lower fees. If you need to buy or sell immediately, you should use a standard limit order (without post-only) or a market order instead.
Another common mistake is relying on post-only for urgent stop-loss scenarios. During sharp price drops or spikes, a post-only stop order may be automatically canceled or fail to execute immediately if the market price gaps past your limit. This can lead to significantly larger losses than intended.
9. In Conclusion
Post-only is an order mode designed by MEXC to help traders reduce transaction fees. When using it, ensure your limit price is set at a sufficient distance from the current market price to avoid being flagged for immediate execution, which would trigger an automatic cancellation. For users who prioritize low trading costs and are not in a rush to execute, post-only is a practical and valuable tool to master.