Understanding Mark Price Formula in Perpetual Contracts

The foundation of fair trading in perpetual futures lies in how prices are calculated and used to determine liquidations. When perpetual contracts first emerged, many traders fell victim to price manipulation and unexpected liquidations triggered by temporary market distortions. The solution? A dual-price system that separates the trigger price (mark price) from the actual transaction price, ensuring traders can’t be unfairly liquidated during market volatility. This is where the mark price formula becomes essential.

Why Dual-Price Mechanism Matters

Market manipulations can cause futures prices to deviate sharply from real-world spot prices on major exchanges. Without proper safeguards, traders could face mass liquidations even during normal market conditions—a scenario that damages both individual traders and overall market confidence. The dual-price approach protects against this by using two prices simultaneously: one for liquidation triggers and one for actual trading.

The mark price formula serves as the anchor for liquidation decisions, calculated to reflect genuine spot market conditions rather than temporary price spikes or manipulation attempts. Meanwhile, the last traded price remains tied to the actual market through a funding mechanism, keeping the two prices aligned over time.

How Mark Price Formula Works

The mark price formula calculates a reference price using three core components:

For newer trading pairs, the formula incorporates the index price plus a decaying funding basis:

Mark Price = Index Price + Moving Average (basis points adjusted by deviation ratio)

The calculation measures mid-price deviations every second and caps the weighting coefficient between 0.1 and 0.9, preventing extreme mid-price movements from distorting the result. This approach has been gradually implemented for selected trading pairs since mid-November 2025.

For established trading pairs, the mark price formula uses a median approach:

Mark Price = Median (Price 1, Price 2, Last Traded Price)

Where:

• Price 1 = Index Price × [1 + Last Funding Rate × (Time Until Funding ÷ 8)]
• Price 2 = Index Price + 2.5-minute Moving Average of (Bid + Ask) ÷ 2 − Index Price

This three-point median method naturally filters out temporary extremes while maintaining responsiveness to genuine market moves.

Mark Price Calculation Under Special Conditions

The mark price formula incorporates adaptive logic for abnormal market situations. If spot exchange index prices become corrupted or data feeds are interrupted, the system shifts to using the platform’s last traded price for mark price calculations. Similarly, when there’s insufficient data to compute the moving average baseline—due to index distortion or other market anomalies—the mark price defaults to the last traded price.

These safeguards ensure the mark price formula continues functioning reliably even during market stress, when fair pricing is most critical.

The Last Traded Price Difference

While the mark price formula determines when liquidations occur, the last traded price represents the actual market price on the platform. These two prices work in tandem: the last traded price anchors to the spot market through the funding mechanism, while the mark price formula acts as the liquidation trigger.

In volatile markets, these prices may temporarily diverge, creating immediate unrealized gains or losses after order execution. Traders should understand this is a paper change, not realized profit or loss—what matters is monitoring the gap between your liquidation price and the mark price to stay safe.

Key Takeaway

The mark price formula represents a critical innovation in perpetual contract design. By decoupling liquidation triggers from transaction prices, exchanges can prevent manipulation-driven liquidations while maintaining market integrity. Understanding how this formula works helps traders make better risk management decisions and avoid preventable liquidations during market swings.