Dynamics behind the borrow operation.
The collateral amount
, can be expressed in the borrowed token value following this formula:
represents the conversion rate between the borrowed and the collateralized asset.
For safety reasons, the total amount of
cannot be borrowed by the user; it is necessary to retain a portion of it within the protocol to safeguard the loan in case of negative fluctuations in the value of the collateralized asset and to guarantee the interest repayment. Therefore, a safety threshold
is devised by the protocol.
is expressed in percentage form, e.g.,
= 0.8 (i.e., 80%), which determines the Loan to Value (LTV).
The granted value is given by the following:
Therefore, the borrowable amount
is calculated as follows:
is the Borrowable to Collateral ratio, and it is calculated as follows:
So, the borrowable amount at the time of borrow is calculated as:
The critical value
represents the liquidation threshold, and it is given in percentage defined such that:
= 90%). When the borrowed amount plus accrued interest reaches down the amount
(in the same currency), the position is considered under-collateralized and must be liquidated.
is the threshold of under-collateralization of the loan. Therefore, the equivalent amount in the borrowed asset is calculated as:
The user will have to pay interest on the loan. Regular payments are not required to simplify the protocol. However, the non-payments may correspond to a decrease in the collateral value, which must be kept above the T threshold. If the user does not pay interest or stabilize its collateral, a liquidator can repay the debt, acquiring collateral control.
The variable state Borrow Balance
represents the actual amount the user must repay to the platform to close the debt position. To clearly understand all the situations that a loan position could incur, four components are defined as follows:
which represents the actual value borrowed by the user, which is initially
. This is checked and updated only when one of the following occurs: Repay Loan (fully/partially or liquidate) and borrow additional asset (collateral value increased).
which is the amount of asset added (borrow additional asset) or subtracted (Repay loan/interest) from the borrow balance.
is the borrow balance of the loan at the time t updated at the last loan operation N. It is calculated as an update of the previous borrow balance and the relative compounded interest, plus/minus the contribution of
is the part of the user debt composed of the accrued interest on the borrowed amount . When the user repays, the accrued interest part of the payment is addressed to the reserve pool.