In perpetuals and futures, a single coin can have multiple prices at the same time. Your chart shows the last traded price, while the exchange’s risk engine may calculate unrealized PnL and liquidation triggers using Mark Price. That’s why beginners run into the classic mismatch: a wick touches a level on the chart, yet liquidation doesn’t happen—or liquidation happens even though the chart “didn’t get there.”
The practical rule is old and reliable: liquidation is a risk-engine procedure, and it is typically triggered by Mark Price, not by last price wicks. Major exchanges explicitly document Mark Price as the reference for liquidation and unrealized PnL. A free liquidation scanner lets you trade from others' liquidations.
The Three Prices You Must Separate
Last Price
The most recent trade price—the one that draws candles. It can jump on thin books or a single aggressive fill.
Index Price
A spot-anchored reference built from multiple spot venues with weights. Bybit describes Index Price as a weighted sum of spot prices from leading exchanges, with weights updated on a schedule.
Mark Price
A fair reference used for risk calculations. It is typically based on Index Price plus a smoothed basis component to reduce unnecessary liquidations caused by abnormal last-price spikes. Both Bybit and Binance describe Mark Price as the liquidation trigger and the basis for unrealized PnL calculations.
Why Exchanges Don’t Liquidate Using Last Price
Because last price is easier to distort: thin liquidity, a single order, or a brief dislocation can print an extreme candle. If liquidation were based on that, forced liquidations would be frequent and exploitable.
Mark Price is the safety mechanism. Binance explains Mark Price as an estimated fair value and notes that liquidations on Futures reference Mark Price.
What Exactly Triggers Liquidation
A position has a liquidation price, and liquidation is triggered when Mark Price reaches that threshold. Bybit states this directly: liquidation occurs when Mark Price reaches the position’s liquidation price.
Practical takeaway:
- a wick can hit a level on last price while Mark Price does not—so liquidation may not trigger;
- Mark Price can reach the threshold even if your chart looks different—so liquidation can still occur.
Why Your Liquidation Price Differs From the Chart
Common operational causes:
- you’re looking at the wrong reference (last vs mark vs index); Binance notes liquidation price and unrealized PnL are based on Mark Price;
- derivatives dislocated from spot (basis/premium), which feeds into Mark Price;
- thin liquidity producing last-price extremes while Mark Price stays more stable.
Stops, Trigger Price, and Another Common Surprise
One more operational detail: what triggers your stop orders. Some venues let you choose the trigger price (last/mark/index) for conditional orders, and that choice changes behavior during spikes. Deribit highlights that stops depend on the selected trigger price.
Rule: check your stop trigger setting once, and don’t leave it to defaults you don’t understand.
A Practical Checklist for Beginners
- Before entering, compare your liquidation price to Mark Price, not to a single candle.
- Keep a margin buffer—liquidation is a maintenance-margin process, not a “pretty level.”
- Avoid high leverage in thin markets—last price wicks are more frequent.
- Reduce activity around major events (news, listings, delistings) where dislocations grow.
- Know your stop trigger price setting.
FAQ
Can I be liquidated if the candle didn’t hit my liquidation price?
Yes—if Mark Price reached it. Liquidations typically reference Mark Price, not last price.
Why do exchanges show three prices?
Last price reflects trades, Index Price anchors spot reference, and Mark Price powers risk calculations and reduces unnecessary liquidations during spikes.
Does Mark Price change my realized PnL?
Mark Price is generally used for unrealized PnL and risk processes; realized PnL is determined by executed trades.
Why does liquidation price move?
Because margin, position size, fees, and maintenance requirements change, and rules differ by cross/isolated modes and by exchange formulas.
What’s the one rule to avoid confusion?
Treat Mark Price as the risk reference, and treat last price as the chart.
Conclusion
In perpetuals, “price” is not a single number. Last Price draws the chart, Index Price anchors a spot reference, and Mark Price runs the risk engine: unrealized PnL and liquidation triggers. Once you internalize that, you stop trading wicks and start managing margin and regime—how leveraged markets have always been traded.