Index & Forward Price Sources

Index Price Source

Accurate and reliable index prices are crucial to our platform. We source index price data from multiple reputable APIs to ensure robustness, reduce the risk of price manipulation, and maintain availability. These prices underpin Rails' core services such as funding and trading metrics calculations.

To ensure reliability and availability, our system uses a multi-sourced cascading fallback approach for index pricing, detailed below:

Primary Source
CoinDesk Aggregate Index API - CCIX
Our main source of index prices.

Backup Source 1	Backup Source 2	Backup Source 3
CoinDesk Aggregate Index API - CCCAGG	Hyperliquid Subscriptions API - Hyperliquid	Kraken's Ticker (Level 1) API
Used if the primary source becomes unavailable.	Acts as a secondary fallback to maintain price availability.	Acts as the last fallback to maintain price availability.

Forward Price Source

Accurate and reliable forward prices are crucial to options valuation. We source forward price data from Deribit’s Get Book Summary by Currency Public API endpoint.

This data supports contract-level mark price and implied volatility calculations. For each live options contract, underlying_price provides the forward-derived price used for valuation. Options use a forward reference price in Black-76, so this price reflects the futures curve for that expiry rather than the current spot price.