A special type of conduit that utilizes third-party borrowing in addition to short-term debt to finance the purchase of long-term assets. For example, an SIV might acquire a portfolio of mortgaged-backed securities with short-term debt plus proceeds from an issue of commercial paper secured by the acquired assets. An SIV must be marked to market (not always an easy task) and portfolio assets sold to repay investors in the event debt cannot be refinanced.