> For the complete documentation index, see [llms.txt](https://smilee-finance.gitbook.io/arbitrum-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://smilee-finance.gitbook.io/arbitrum-docs/protocol-design/dvps.md).

# DVPs

Smilee protocol is based on two main contracts:

1. **Decentralized Volatility Products (DVPs).**
2. **Earn Vaults.**

{% hint style="warning" %}
At the smart contract level, the Earn Vault is simply called Vault.
{% endhint %}

**Both DVPs and Earn Vaults are defined by:**

* A Reference Token (e.g. ETH, wBTC, …)
* A Maturity Frequency (e.g. daily, weekly, …)

## Impermanent Gain DVP

DVPs are smart contract that can replicate any kind of volatility payoff. 

{% hint style="warning" %}
At the smart contract level, Impermanent Gain is an instance of the DVP.
{% endhint %}

DVPs are used to mint and trade Impermanent Gain Options, which can be either IG Bull or IG Bear and are represented by **ERC721 Tokens.**

{% hint style="info" %}
Impermanent Gain Smile is obtained by purchasing both IG Bull and IG Bear.
{% endhint %}

To know more about Impermanent Gain Bull, Bear, or Smile please refer to the [Trade](/arbitrum-docs/impermanent-gain/trade.md) Section.