When trading in USDⓈ-M perpetual futures, you may fail to place an order or experience unfilled orders due to multiple factors. The following are possible reasons.

Reasons for Order Failure

1. Insufficient margin: You currently have other open orders that utilize the same margin.

2. Order trigger failure: You have insufficient margin or position size to close when a trigger or TP/SL order is triggered.

3. Position size limit: Your position size exceeds the limit supported by the current leverage.

4. Amount limit: The order amount falls below the minimum threshold or exceeds the maximum limit.

5. Price limit: The price you set up for an order is either too low, below the minimum order price, or too high, surpassing the maximum order price.

6. Quantity limit for unfilled orders: The maximum number of unfilled orders for all symbols is limited to 50. If the number of orders exceeds the limit, you cannot place further orders. 

7. Post Only order filled immediately: If a Post Only order is filled immediately, the order will be canceled.

8. A FOK (Fill or Kill) order cannot be immediately and fully filled: When placing a FOK order, if the order cannot be immediately filled in its entirety, it will be canceled.

9. An IOC (Immediate Or Cancel) order cannot be immediately filled: When placing an IOC order, if the order is not immediately filled in its entirety, the unfulfilled part will be canceled immediately.

10. If you have no positions in One-way Mode, you can not select the “Reduce-Only” option to place an order.

Reasons for Unfilled Order Failure

1. Significant deviation from market price: The order price does not match any orders in the market depth pool. Additionally,  when the position size is too large, market price fluctuations during partial execution result in price deviation, impeding the execution of remaining positions.

2. Price not match: When placing a trigger or TP/SL order, if the market price reaches the trigger price, the system places the order at the specified price. Orders are matched based on price priority and then time priority. If there are no matching counterparty orders, the order cannot be executed.