Loan borrow

After a user has locked up their collateral, they can borrow against it. The amount the user has borrowed of a given asset is defined as $B_t$​ whereas the borrow balance of a given asset $BB_t$​ is defined as the amount borrowed plus accrued interest.

The borrow factor $BF$​ represents the effective borrowed amount given a borrow, in percent terms. For example, a more volatile asset may have $BF=110$​% (for $10 borrowed, it is as if $11 has been effectively borrowed) whereas a less volatile asset may have $BF=100$​%.

Consider a user who borrows multiple assets. The total borrowed amount $TB_t$ at time t for a given loan’s borrows is:

$$TB_t=\sum_{i=ASSET,V/S}^{borrowed}BB_{t_i}*P_i*BF_i$$

Where:

• $BB_t$ denotes the current user borrow balance of a borrow,

• $P_i$ is the price of the borrowed asset,

• $BF_i$ is the borrow factor,

• the subscript $i$ represents each borrow of the loan where a borrow is a unique pairing of asset and variable/stable rate.

The total borrowed $TB_t$ must not exceed the borrowable amount $BA_t$, otherwise the loan can be liquidated by a third party:

$$TB_t \leqslant BA_t$$

If a borrow or reduce collateral operation would lead to the above condition being violated then it will be rejected by the protocol.