The index price is based on the latest transaction price of the underlying currency pair on the mainstream exchanges in the market and the median of the buy one sell one, and the weighted average. The calculated index price can represent the fair market price of the currency pair.

Below are the source exchanges and calculated weights for each contract index.

USDT contract

contract

FTX

Huobi

Binance

OKex

BTCUSDT

25%

25%

25%

25%

ETHUSDT

25%

25%

25%

25%

coin-margined contracts

contract

FTX

Coinbase

Bitfinex

BTCUSD

33.3%

33.3%

33.3%

ETHUSD

33.3%

33.3%

33.3%

[The above data and indicators may be adjusted in real time according to market conditions, and the adjustment will not be notified separately]

Sample data sampling: every 1 second (determined according to the index update interval) to obtain the latest price of the exchange in the table through the API.

**Exponential exception handling**

Remove invalid prices:

When the price of a source exchange is not updated within 40,000ms or the updated value is too far from the previous value, we will all consider its price to be an oolong, and reset the weight of the exchange to 0 in this calculation.

Abnormal Price Correction:

When the price of an exchange deviates significantly from other exchanges, and its price deviates from the median of all source exchanges (including the exchange itself) by ±3%, the exchange's price is traded on a sample basis The median price of the exchange is ±3% for calculation (when the median deviation of USDT price reaches ±0.3%, the price of the exchange is calculated as the median ±0.3% of the sample exchange price).