Reserve Loans
Reserve Loans are a core financial primitive introduced by Polaris, allowing users to borrow ETH directly from the bonding curve reserve using fpETH as collateral.
As described in the fpETH section, fpETH represents the steadily growing floor component of pETH. Since the fpETH price in ETH is guaranteed to only increase, changes in the ETH price cannot cause the position to become undercollateralized. This removes the need for liquidations and allows users to borrow up to 100% of the floor value represented by their fpETH.
With this feature, borrowers gain ETH liquidity without giving up fpETH yield, making highly capital-efficient looping strategies possible.
Loan Mechanics
Instead of paying a conventional borrowing interest rate, Reserve Loans apply a time-weighted performance fee, which is deducted directly from the increase in the fpETH floor price over the lifetime of the loan.
This allows users to benefit from the growth of the fpETH floor while passively paying for the extra liquidity they access.
As described in the dedicated Fee Router section, the fees generated by Reserve Loans are recycled back into the Polaris ecosystem, becoming part of the value distributed throughout the protocol.