A structured investment vehicle (SIV) is like a special container set up by banks to hold large amounts of money. The money can come from investments like stocks, bonds or other similar kinds of investments. The SIV then uses that money to invest in other types of assets and make more money. The SIV pays the initial investors, like banks, a return on their investment. So the bank uses a SIV to invest money to make more money, but it also helps to reduce their risk because if one of the assets does not do so well, the SIV will have other types of investments that can make up for it.