StaFi is a DeFi protocol that unlocks the liquidity of staked assets. Users can stake their PoS tokens through StaFi and receive rTokens in return, which allows them to trade while earning staking rewards. rFIS is the staking asset exchange certificate issued by StaFi to users. When a user stakes FIS (StaFi’s native token), StaFi calculates the amount of rFIS they receive based on the current exchange rate between FIS and rFIS. While holding rFIS, StaFi calculates the redeemable FIS amount for users based on the deposit income generated by FIS.