The index price represents the market consensus price of the underlying asset (the corresponding spot of the futures). It is derived from the weighted average of quotes from multiple spot exchanges, including Pionex, Binance, Bitfinex, Gate.io, OKX, Coinbase, Huobi, and MEXC, adjusted based on data usability and weighting factors. Data usability testing includes assessing the timeliness and validity of the data. The quoted price of reference exchanges that have passed the usability test are weighted according to trading volume. Ultimately, the index price for each trading pair is calculated by multiplying the quoted prices from various major spot exchanges by the adjusted weighting.

**Calculation Formula**

When the number of valid prices is >= 3:

- Obtain the median value M as the reference (for an even number of data, take the average of the middle two values)
- If the price from a particular exchange, Px, is greater than (1 + 3%) * M, set Px = (1 + 3%) * M
- If the price from a particular exchange, Px, is less than (1 – 3%) * M, set Px = (1 – 3%) * M
- Index price = Weighted average of all valid data

When the number of valid prices is 2:

- Index price = Average of all valid data

When the number of valid prices is 1:

- Index price = This valid data point