By Wikipedia
The shadow banking system is the collection of non-bank financial intermediaries that provide services similar to traditional commercial banks. It is sometimes said to include entities such as hedge funds, money market funds and structured investment vehicles (SIV), but the meaning and scope of shadow banking is disputed in the academic literature. Investment banks as well as commercial banks may conduct much of their business in the shadow banking system (SBS), but most are not generally classed as SBS institutions themselves. At least one financial regulatory expert has said that regulated banking organizations are the largest shadow banks.
