The modern financial system features complicated intermediation chains, with each layer performing some degree of credit/maturity transformation. We develop a dynamic model where an ultimate borrower obtains funds from overlappinggeneration households via layers of funds, forming a credit chain. Each intermediary fund in the chain faces rollover risks. The model delivers new insights regarding the benefits of intermediation via layers: by shortening the maturity of liquidated assets, the chain structure insulates interim negative fundamental shocks and protects the underlying cash-flows from being discounted heavily during bad times. We show the equilibrium chain length minimizes run risks and is constrained efficient.