Turning a future cashflow into tradable, bond-like securities. Creating such asset-backed securities became a lucrative business for financial firms during the 1990s, as they invented new securities based on cashflow ranging from future mortgage and credit-card payments to bank loans, movie revenue and even the royalties on songs by David Bowie (so-called Bowie-bonds). Securitization has many benefits, at least in theory. Issuers gain instant access to money for which they would otherwise have to wait months or years, and they can shed some of the risk that their expected revenue will not materialize. By selling securitized loans, investment banks are able to finance their customers without tying up large amounts of capital. Investors can hold a new sort of asset, less risky than unsecured bonds, giving them the risk-reducing benefit of diversification. But there are dangers. The future cashflow underlying the securities may flow earlier or later than promised, or not at all.