Though not all funds are fully transparent, the total wealth of all SWFs is estimated somewhere between $2 trillion and $3 trillion.

Typically, countries create SWFs for two reasons: 1) if a nation is resource dependent, its excess reserves can be invested into other projects to help diversify its economy; and 2) to create a reserve fund to manage excess reserves and increase yield.

SWFs have grown rapidly in both number and size over the past decade and have been an important source of liquidity in times of duress. Several came under public scrutiny in 2008 and 2009 as they made cash infusions to failing financial institutions in return for ownership interests in those institutions.

SWFs are quickly becoming more intertwined in the global financial markets through their investments in financial assets, infrastructure and both private and public companies. The rapid growth of SWFs and their growing role in the global financial markets has been an area of increasing concern for policymakers in the U.S. as well as abroad due to their general lack of transparency.