# Elastic Supply Assets

Elastic supply assets, or **“rebasing”** assets, were originally constructed by [Ampleforth](https://www.ampleforth.org/) as a mechanism to provide stable price, without losing exposure to value gains. Rebasing assets transfer volatility of an asset from *price* to *supply*.

This mechanism has a very nice quality in that it allows for stable contracts. For example (taken from the AMPL website):

> Imagine Evan and Micah enter into a bet:\
> \
> \&#xNAN;*"If the Lakers make it to the 2022 NBA conference finals, Micah will pay Evan 10 coins. Otherwise, Evan will pay Micah 10 coins."*
>
> We would not want to denominate this bet using Bitcoin, because Bitcoin's price volatility makes for an unstable contract obligation.

Rebasing assets' price stability make them great assets for contract denomination.

## Clean Integrations

Another very important benefit of rebasing assets is that they naturally *abstract price information* away from integrations. 

For example, a traditional DeFi lending platform like Aave needs a complex oracle system to calculate collateralization and relative values of assets. This adds extra complexity and risk to the system - If the oracle goes wrong, users could be wrongfully liquidated and pools could be drained.

Lending applications built with rebasing assets don't actually need price data - they only need access to the balances of the asset. Value is expressed directly in the contract's changing balance - the price can always be assumed to be stable and around $1.  

## Buttonwood Rebasing Tokens

Buttonwood extends this concept with the `ButtonToken` - creating the ability to turn *any crypto-asset* (BTC, ETH, etc.) into a rebasing asset, as long as it has a solid price-feed oracle. 

{% content-ref url="elastic-supply-assets/buttontoken" %}
[buttontoken](https://docs.prl.one/buttonwood/learn/elastic-supply-assets/buttontoken)
{% endcontent-ref %}

Buttonwood also created the `UnbuttonToken` - the inverse of the `ButtonToken`. It turns elastic supply assets into fixed-supply assets. 

{% content-ref url="elastic-supply-assets/unbuttontoken" %}
[unbuttontoken](https://docs.prl.one/buttonwood/learn/elastic-supply-assets/unbuttontoken)
{% endcontent-ref %}