Mark Price and Last Price are two distinct pricing mechanisms that determine your trading outcomes on Sui-based perpetual markets. Understanding their difference directly impacts your position valuation and liquidation risk.
Key Takeaways
- Mark Price protects against market manipulation on Sui exchanges
- Last Price reflects actual trade execution value
- Liquidations trigger based on Mark Price, not Last Price
- The two prices converge during normal market conditions
- Funding payments calculate using Mark Price
What is Mark Price on Sui
Mark Price represents the fair estimated value of a perpetual contract on Sui, calculated using a combination of the underlying index price and a time-weighted average. Exchanges derive this value from multiple external data sources to create a stable reference point. According to Investopedia, mark price mechanisms exist to prevent artificial price volatility from triggering unnecessary liquidations. Sui protocols update Mark Price continuously based on market conditions.
What is Last Price on Sui
Last Price is the actual execution price of the most recent trade matched on the Sui order book. This value fluctuates with every completed transaction between buyers and sellers. Last Price determines exactly what you pay or receive when opening or closing positions. It reflects real-time supply and demand dynamics at the moment of trade execution.
Why the Difference Matters
The distinction between Mark Price and Last Price serves critical protective functions for Sui traders. Without Mark Price, bad actors could manipulate the Last Price to trigger cascade liquidations at favorable levels. The time-weighted calculation smooths out short-term price anomalies that do not reflect genuine market value. This mechanism ensures that funding rates remain fair and positions liquidate only when truly necessary. Traders monitoring only Last Price risk misjudging their actual margin health.
How Mark Price Calculation Works
Mark Price on Sui follows this core formula:
Mark Price = Index Price × (1 + Funding Rate Premium)
The Index Price comes from weighted averages of prices across major spot exchanges. The Funding Rate Premium adjusts based on the difference between perpetual contract price and spot index. When funding rates turn positive, long positions pay shorts, and the premium component increases accordingly. Sui protocols recalculate this value at regular intervals, typically every eight hours for most perpetual markets.
The complete calculation includes these components:
Mark Price = Median(Price1, Price2, Contract Price)
Where Price1 = Spot Index × (1 + Recent Funding Rate)
Where Price2 = Spot Index + Moving Average (30-minute basis)
The median selection prevents extreme values from either component dominating the final price. This structure creates a built-in safety buffer against sudden price swings.
Used in Practice
When you open a long position on a Sui perpetual market, your initial margin calculates against the Last Price you executed. However, your unrealized profit and loss display using Mark Price. If Mark Price falls below your liquidation threshold while Last Price remains higher, your position stays open. Conversely, if Last Price spikes due to low liquidity but Mark Price holds steady, your position does not liquidate immediately. Successful Sui traders track both values simultaneously, watching for divergence that signals potential manipulation or liquidity gaps.
Risks and Limitations
Mark Price protection has inherent limitations during extreme market conditions. During flash crashes, both prices may converge downward rapidly, and protection mechanisms may lag slightly behind actual price movements. Liquidity fragmentation across Sui’s fragmented trading venues can create price discrepancies between different protocols. Historical data from traditional markets, as noted by the Bank for International Settlements (BIS), shows that even sophisticated pricing models require time to adapt to unprecedented volatility. Index price sources themselves carry operational risks if major exchanges experience downtime.
Mark Price vs Last Price on Sui
Mark Price operates as a calculated reference value designed for stability and fairness in position management. Last Price represents actual transaction values where trades execute in real time. Mark Price governs liquidation decisions and funding rate calculations across Sui protocols. Last Price determines your entry cost, exit proceeds, and realized PnL. The two values should remain close during healthy market conditions. Large deviations indicate either market stress or potential arbitrage opportunities between trading venues.
What to Watch
Monitor the spread between Mark Price and Last Price before placing large orders on Sui. Wider spreads during volatile periods increase the risk of unexpected liquidation triggers. Check the funding rate direction to anticipate whether Mark Price will trend above or below spot index prices. Review the specific Mark Price calculation methodology your Sui exchange uses, as protocols vary in their median selection and time-weighting approaches. Track historical liquidation levels where Mark Price clusters, as these become technical reference points for other traders.
Frequently Asked Questions
Can I be liquidated if Mark Price is above my liquidation price but Last Price drops below it?
No, liquidations trigger exclusively based on Mark Price levels, not Last Price execution values.
How often does Mark Price update on Sui exchanges?
Most Sui protocols update Mark Price continuously or at short intervals, typically every few seconds during active trading sessions.
Why did my stop-loss execute at a different price than I set?
Stop-loss orders execute at the best available Last Price, which may differ from your specified trigger price during fast-moving markets.
Does Mark Price affect my trading fees?
Trading fees calculate based on Last Price at execution, while funding payments settle using Mark Price differences.
What happens if the Index Price source goes offline?
Sui protocols typically switch to backup data sources or switch to emergency calculation modes that prioritize Last Price when primary feeds fail.
How do I calculate my position value using Mark Price?
Subtract the Mark Price from your entry price, multiply by your position size, and account for the leverage multiplier applied to your margin.
Is Mark Price always higher than Last Price?
No, Mark Price can trade above, below, or equal to Last Price depending on funding rate conditions and market sentiment direction.