> For the complete documentation index, see [llms.txt](https://v1.docs.volmex.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://v1.docs.volmex.finance/indices/methodology.md).

# Methodology

At a given time, volmex.finance indices factor in eight options which meet the following criteria:

* In-the-money call and put closest to 15 days from expiration 
* Out-of-the-money call and put closest to 15 days from expiration
* In-the-money call and put closest to 45 days from expiration
* Out-of-the-money call and put closest to 45 days from expiration

Options data is sourced in real-time from [Deribit](https://www.deribit.com/), the leading crypto options exchange. By running respective data through an inverted [Black-Scholes formula](https://en.wikipedia.org/wiki/Black%E2%80%93Scholes_model), an output is generated (current index value), which aims to measure the 30-day implied volatility of the underlying asset (e.g. ETH, BTC, etc). The index output is the mean of the IVs. 

Mid price of options is used in the calculation.