A crypto futures position can be liquidated even when the last price shown on the chart has not touched its liquidation price. The reason is that KTX uses the mark price—not simply the most recent trade—to assess liquidation. The last price records where the latest transaction occurred; the mark price is a separate fair-value reference designed to reduce the influence of isolated trades and short-lived order-book distortions.
This distinction affects more than one number on the trading screen. It changes how traders interpret unrealized profit and loss, stop-loss placement, liquidation distance and the price they can actually receive when closing a position.
The Price on the Chart Is Not Always the Liquidation Price
Imagine a BTC perpetual long with a displayed liquidation price of 65,000 USDT. The contract's last trade is still at 65,120, but the mark price falls to 65,000 because broader spot-market references decline quickly. The position can enter liquidation before the last-price chart prints 65,000.
The reverse situation is also possible. A single small trade may push the last price briefly below 65,000 while the mark price remains above the liquidation line. That isolated print does not by itself trigger liquidation on KTX. The system evaluates whether the mark price has reached the position's liquidation threshold.
Mark Price and Last Price Answer Different Questions
| Price | What it represents | Main use | Main limitation |
|---|---|---|---|
| Mark price | A fair-value reference derived from broader market inputs and contract pricing rules | Liquidation checks and displayed unrealized PnL on KTX | It may differ from the price available in the local order book |
| Last price | The price of the most recently completed trade in that contract | Recent trading activity, chart updates and order-trigger references where specified | One small or unusual trade can move it temporarily |
| Fill price | The actual average price received when an order executes | Realized trading result | It depends on order type, spread, depth and slippage |
The last price is observable and concrete: a buyer and seller just traded there. It does not guarantee that the next order will execute at the same level. The mark price is not a tradable quote. It is a risk-control reference. A trader cannot submit an order directly “at the mark price” unless matching orders happen to exist near that level.
Why Exchanges Use Mark Price for Liquidation
Futures order books can move sharply when liquidity is thin, a large market order crosses several levels or an isolated trade occurs away from the wider market. If liquidation depended only on the last trade, a brief local price spike could close leveraged positions even when the broader market had not moved to the same extent.
KTX uses a mark-price mechanism to reduce that risk. Its mark price draws on broader spot-market references and fair-value adjustments, rather than relying on one futures fill. This does not prevent liquidation or guarantee that the mark price will move slowly. It gives the risk engine a more representative reference during ordinary and stressed conditions.
For the wider margin process, see how crypto liquidation works when account equity becomes insufficient.
Which Price Determines Unrealized and Realized PnL?
On KTX, the mark price is used to calculate and display unrealized PnL for open futures positions. For a simplified linear long position:
Unrealized PnL = Position Size × (Mark Price − Average Entry Price)
For a short, the price difference is reversed. This estimate changes as the mark price moves and can affect the account's margin buffer. It is not the final amount that will be realized.
When the position closes, realized PnL depends on the actual fill price, then requires adjustments for trading fees and applicable funding payments. If the last price is 100, the mark price is 99.8 and a market sell fills at an average of 99.6, the closing result uses 99.6. Neither the last price nor the mark price promises an exit at that level. The realized and unrealized PnL guide explains how to reconcile the final result.
A Worked Liquidation Example
Consider a hypothetical BTC perpetual long with these values:
- Average entry price: 70,000 USDT
- Displayed liquidation price: 65,000 USDT
- Last price: 65,120 USDT
- Mark price: 65,000 USDT
The position reaches the liquidation condition because the mark price has touched 65,000, even though the most recent contract trade remains 120 USDT higher. If the last price instead prints 64,950 while the mark price remains at 65,080, the last trade alone does not satisfy the mark-price liquidation condition.
The displayed liquidation price can change before either scenario occurs. Adding or removing margin, changing position size, funding deductions, fees and movements in other positions under cross margin can alter the available buffer. The price shown by a calculator is therefore an estimate based on the current inputs, not a permanent boundary.
Why a Stop-Loss May Not Prevent Liquidation
A stop-loss and the liquidation engine can observe different prices. KTX documentation states that liquidation uses the mark price, while a stop-loss may use the last price under the applicable order rule. If the mark price reaches the liquidation line before the last price reaches the stop trigger, risk control can take over the position first.
Placement also matters. For a long position with liquidation at 65,000, a stop placed at 64,500 is beyond the liquidation boundary. A falling market encounters the liquidation price first. Even a stop above the boundary is not a guarantee: a rapid move, insufficient depth or slippage can delay or worsen execution.
Traders should verify the trigger-price setting available for the specific order, then leave a practical buffer between a planned exit and the liquidation price. A stop-loss is a risk-management instruction, not protection against every market condition.
How Margin Mode Changes the Calculation
Under isolated margin, the collateral assigned to one position generally defines that position's risk buffer. Adding isolated margin can move its estimated liquidation price, while losses are contained to the amount allocated under the product rules.
Under cross margin, eligible positions share account collateral. Profit, loss, fees and margin use elsewhere in the account can change the liquidation price of a position even if that contract's last price barely moves. The cross margin and isolated margin comparison explains the different scope of collateral exposure.
How to Monitor Both Prices on KTX
Before opening a leveraged position, record the entry price, mark price, displayed liquidation price, margin mode and planned exit. During the trade, monitor the distance from the mark price to liquidation rather than relying only on the latest candle. Also review funding, account equity and any other positions sharing cross margin.
Eligible users can register for a KTX account and inspect the live mark price, last price, order book and position data on the KTX BTC/USDT perpetual market. Product parameters can vary by contract, so confirm the current trading rules before placing an order.
Frequently Asked Questions
Which price triggers liquidation on KTX?
The mark price triggers liquidation when it reaches the position's liquidation threshold. The last price alone does not determine the liquidation check.
Can I close a position at the mark price?
Not directly. The mark price is a reference rather than an executable quote. A closing order trades against available bids or asks, so the realized result depends on actual fills.
Why is my unrealized PnL different from the chart move?
The open-position display may use mark price, while the chart commonly emphasizes last price. Fees, funding, average entry price and position size also affect the number shown.
Can the mark price move faster than the last price?
Yes. When broader spot references change quickly but the local futures order book trades slowly, the mark price can reach a risk threshold before the last price. The opposite divergence can also occur.
Risk Disclaimer
This article is for informational and educational purposes only and does not constitute financial or investment advice. Futures trading involves leverage, funding, slippage and liquidation risk, including possible loss of all posted margin. Price references, triggers and contract parameters may change. Review the live KTX contract rules and manage position size and collateral according to your own circumstances.