A structured investment vehicle (SIV) is a non-bank financial institution established to earn a credit spread between the longer-term assets held in its portfolio and the shorter-term liabilities it issues. They are simple credit spread lenders, frequently "lending" by investing in securitizations, but also by investing in corporate bonds and funding by issuing commercial paper and medium term notes, which were usually rated AAA until the onset of the financial crisis. They did not expose themselves to either interest rate or currency risk and typically held asset to maturity. SIVs differ from asset-backed securities and collateralized debt obligations (CDOs) in that they are permanently capitalized and have an active management team.