# Sustainability

## The Two-Token Model

Skeleton Money operates with two key tokens, and both tokens are used to support the growth and stability of the other, depending on market activity at any given time.\
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As a multi-utility token, the performance of $BONE is key to maintaining the success of Skeleton Money. In order to achieve this, $BONE is consistently purchased by the Skeleton Money treasury. This is enabled via the consistent yield earned by rehypothication of both the treasury $S and the staked assets. 

1. $sKULL 
   1. $sKULL is an over-collateralised yield-bearing token, backed by #S
   2. $sKULL is used all throughout the Skeleton Money protocol 
2. $BONE 
   1. $BONE drives rewards and provides additional opportunities for staking.
   2. $BONE will also serve as a governance token