Collateral eligibility criteria could include asset type, issuer, currency, domicile, credit rating, maturity, index, issue size, average daily traded volume, etc. Both the lender (repo buyer) and borrower (repo seller) of cash enter into these transactions to avoid the administrative burden of bi-lateral repos. In addition, because the collateral is being held by an agent, counterparty risk is reduced. A tri-party repo may be seen as the outgrowth of the '"due bill repo". A due bill repo is a repo in which the collateral is retained by the Cash borrower and not delivered to the cash provider. There is an increased element of risk when compared to the tri-party repo as collateral on a due bill repo is held within a client custody account at the Cash Borrower rather than a collateral account at a neutral third party.