The Index Price is the benchmark price of a Perpetual Contract, calculated from real-time prices of multiple independent external data sources, and it is used to determine the Mark Price, the Funding Rate and when a position is liquidated.

What the Index Price Is Used For

The Index Price is the core pricing benchmark for Perpetual Contracts. The Index Price is used to determine:

• - Mark Price: the reference price used to calculate the profit and loss (PnL) of your position and to trigger forced liquidation. For details, see the Contract Mark Price article.
• - Funding Rate: the benchmark for periodic payments between long positions and short positions.
• - Liquidation Trigger: when the Mark Price reaches the liquidation price, the position is closed.

A stable, fair, and manipulation-resistant Index Price is the foundation of a fair trading experience.

Data Sources for the Index Price

The Index Price System connects to two categories of external data sources:

1. 1. Traditional financial market prices: Gold Spot quotes (for example, the Mid Price, which is the midpoint between the bid and ask prices) from multiple internationally recognized financial institutions, covering major global trading sessions.
2. 2. Major cryptocurrency exchange prices: index prices (not the latest trade price) from leading cryptocurrency exchanges. These cover gold token trading pairs quoted in stablecoins such as USDT and USDC. Stablecoins are cryptocurrencies designed to hold a steady value against the US dollar (USD). All of these prices are converted to USD using real-time exchange rates.

These data sources are independent and distributed. If a single source has an anomaly, it does not significantly affect the final Index Price. This helps prevent manipulation and avoids relying on a single point of failure.

How the Index Price Is Calculated and Filtered

The system checks each data source at all times to filter out anomalous data:

• - Timeliness Check: data delayed beyond the threshold is treated as invalid.
• - Price Deviation Filter: if a source’s price deviates too far from the historical price or from the median of all sources, that source is temporarily excluded.
• - Observation Period Validation: newly connected data sources must run stably for a period of time before they are formally included in the calculation.
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Example Calculation

Suppose the latest bid prices of a contract at three exchanges are the ones in the spreadsheet. If the prices are weighted by trading volume, with weights of A: 0.5, B: 0.3 and C: 0.2, the contract Index Price is:

Index Price = 10,020 × 0.5 + 10,010 × 0.3 + 10,030 × 0.2 = 10,019

This value is the contract Index Price displayed to users on the platform.

What Happens When a Data Source Fails

When a data source fails, for example because of a network interruption or exchange downtime, the system does the following:

• - Automatically removes the failed source and redistributes its weight to the other valid sources, so the Index Price continues to be published.
• - When the failed source recovers, does not let the price jump instantly. Instead, it uses a linear transition, typically about 60 seconds, to move smoothly from the current price to the new price that includes the recovered source. This avoids price spikes.
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As a result, the price series stays continuous and stable, with no abnormal fluctuations caused by switching between sources.

What Happens If All Data Sources Are Unavailable

In the extremely unlikely event that all external data sources become unavailable at the same time, the system does the following:

• - Uses the most recent valid Index Price, as long as it is within its validity period.
• - If recovery takes too long, triggers an alert and hands the issue to the operations team for manual intervention, to keep trading as continuous as possible.
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How the Index Price Ensures Fairness

• - Multi-source cross-validation: the system does not rely on a single price provider, so the risk is spread across sources.
• - Fully automated anomaly filtering: all cleansing rules are transparent and applied without human intervention.
• - Real-time monitoring and alerts: the system monitors all data sources 24/7. Any anomaly triggers an alert and is handled automatically.
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The platform is committed to a transparent, fair, and stable trading environment. For further questions about the Index Price, see platform announcements or contact customer support.