Pools of money derived from a country's reserves, which are set aside for investment purposes that will benefit the country's economy and citizens. The funding for a sovereign wealth fund (SWF) comes from from central bank reserves that accumulate as a result of budget and trade surpluses, and even from revenue generated from the exports of natural resources. The types of acceptable investments included in each SWF vary from country to country; countries with liquidity concerns limit investments to only very liquid public debt instruments.

|||Some countries have created SWFs to diversify their revenue streams. For example, the United Arab Emirates (UAE) relies on oil exports for its wealth; therefore, it devotes a portion of its reserves to an SWF that invests in other types of assets that can act as a shield against oil-related risk.

The amount of money in these SWF is substantial. As of May 2007, the UAE's fund was worth more than $875 billion. The estimated value of all SWFs is pegged at $2.5 trillion.