The EOSX, XLMX, and XMRX USD-denominated spot rates are based on trading activity observed on leading digital currency exchanges. To maximize replicability of their value in the live spot markets, rates are dynamically adjusted in real time based on liquidity, price discrepancies, and market anomalies. TradeBlock’s index methodology is guided by the framework defined by IOSCO’s Principles for Financial Benchmarks for the calculation and governance of its indices. The EOSX Index includes markets that are liquid in both EOS/USD & EOS/XBT crosses, which incorporate TradeBlock’s XBX index rate to offer a consolidated EOS/USD reference rate. Similarly, the XLMX Index includes markets that are liquid in XLM/USD & XLM/XBT crosses while the XMRX Index includes those that are liquid in XMR/USD & XMR/XBT crosses.

https://tradeblock.com/blog/announcing-new-indices