Each index price is computed based on order book data from a number of spot exchanges. Currently, Thalex uses the latest prices from Bitstamp, Coinbase Pro, and LMAX Digital.

The calculation has four steps:

- Obtain a list of prices from constituent exchanges. The price of an exchange is calculated as the average of best bid and ask in the order book.
- Calculate the median of available prices.
- Cap each price to deviate at most 0.5% from the median.
- Calculate the simple average of capped values to obtain the Index.

Shown as a formula with available exchange prices denoted as: