Repos are increasingly trading in international money markets. Repos are usually loans exchanged against securities which are taken as collaterals to mitigate credit risk. However, some risk still remains: the seller may default by not repurchasing the securities at the due date. Therefore, the buyer can recover the amount lent by liquidating the securities. However, the securities may then have lost value due to market movements. In particular:
选项：

A: If the value of the collateral drops below the required margin, then the borrower may be subject to a margin call, or the repo may be repriced in which the value of the loan is reduced
B: The main benefit of repos to buyers is that the repo rate is higher than borrowing from a bank
C: Repurchase agreements are long-term collateralized loans used by major financial institutions to obtain funding
D: If the value of the security rises, the buyer will be at a loss; if the value decreases, the borrower stands neither to benefit nor be at a loss