Academy Beginners Tutorial Article

II. USDT Sustainable Contracts: Index Price Calculation Rules


To ensure the spot index price accurately reflects the spot market price of each token, we have carefully selected the market prices of 3 or more major exchanges as the weighted index constituents for each token. Measures are introduced to handle abnormal situations.

1. Spot Index Constituents

2. Spot Index Price Calculation

a. The price and volume of each index constituent is retrieved from the selected exchanges in real time;

b. If the relevant exchange is under maintenance, or if any constituent price/volume has not updated for more than 30 minutes, the constituent data will be temporarily treated as invalid and excluded from index calculation;

c. For trading pairs with BTC as the quote currency, the prices will be converted to USDT by multiplying the OKEx BTC/USDT index;

d. The final calculation depends on the number of exchanges with valid data, details are as follows:

  • More than 3 exchanges with valid data: apply equally-weighted price average (however, if the price of any exchange deviates more than 3% from the median price of all exchanges, the exchange’s price will be bounded within median price x 0.97 and median price x 1.03);
  • Only 2 exchanges with valid data: apply equally-weighted price average;
  • Only 1 exchange with valid data: its last traded price will be used as the index price directly;