> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fairground.fi/llms.txt
> Use this file to discover all available pages before exploring further.

# Pricing

> The index price **_is_** the mark price

Fairground uses a **single oracle price** for each market. Instead of maintaining a separate mark price for the perpetual and an index price that tracks the underlying asset, the protocol uses only the oracle price.

## Why it matters

On most perps protocols, you juggle a mark price (used for liquidations, PnL) and an index price (spot reference, and funding). Fairground simplifies this: **the oracle price is the price**. It is used for everything, order execution, PnL calculation, margin calculations, liquidation, and fee assessment.

## How it updates

The oracle price is pulled fresh at the start of each protocol action: matching, liquidation, and ADL. All orders processed within a single matching cycle execute at the same oracle price and as a result, two orders matched in the same block can execute at different prices if the oracle price changes between them.