> For the complete documentation index, see [llms.txt](https://docs.extended.exchange/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.extended.exchange/extended-resources/trading/oracle-prices/crypto-markets.md).

# Crypto Markets

### Order Book Markets

**Overview**

For crypto assets Extended relies on Mark and Index Prices obtained from 5 nodes of an independent Oracle Provider, [Stork](https://www.stork.network/):

* Mark Prices are used to determine the liquidability of accounts and calculate positions' unrealized PnL.
* Index Prices are used for the calculation of Funding Payments. For detailed information on the calculation of Funding Payments, please refer to the section on [Funding Payments](/extended-resources/trading/funding-payments.md#crypto-markets).

For a deeper understanding of the approach Stork employs to define Mark and Index Prices, explore Stork's comprehensive [documentation](https://docs.stork.network/).

Utilizing independent Oracle Providers like Stork helps prevent potential price manipulation and ensures an equitable and accurate reflection of asset values within the Extended ecosystem.

**Price Denomination**

Both, Mark and Index Prices sourced from Stork are USD denominated. This means that on Extended USD PnL is settled in USDC given USDC margin.

### RFQ Markets

For crypto RFQ markets, Index and Mark Prices are provided by [RedStone](https://redstone.finance/), referencing Binance Index and Mark Prices. k-prefixed markets (e.g. kFLOKI) reference 1,000 units of the underlying token.