Many people who trade contracts often confuse the mark price with the latest traded price. In fact, the mark price is the reference price the platform uses to reduce the risk of liquidation caused by abnormal trades, while the latest traded price is the real execution price. When you notice that the price hasn’t moved but your unrealized profit and loss is jumping, first check whether the mark price is changing. Next time, open the contract interface and compare using the top-right corner—you’ll know what’s going on.