The agreement is a contract enforceable under relevant law, which is often specified in the agreement. As payment for the loan, the parties negotiate a fee, quoted as an annualized percentage of the value of the loaned securities. If the agreed form of collateral is cash, then the fee may be quoted as a "short rebate", meaning that the lender will earn all the interest that accrues on the cash collateral and will "rebate" an agreed rate of interest to the borrower. Key lenders of securities include mutual funds, insurance companies, pension plans, exchange-traded funds and other large investment portfolios.