# 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.