Leverage partnerships with private sector firms. Funds for the sovereign wealth fund can come in several ways. The most widely recognized sources are the surplus reserves from state-owned natural resource revenues, trade surpluses, bank reserves that may be accumulated from budgeting excesses, foreign currency operations, money from privatizations, and governmental transfer payments. In general, sovereign wealth funds usually do something. Some sovereign wealth funds are used by countries as a kind of venture capital for the private sector. Like any type of investment fund, SWFs have objectives, terms, risk tolerances, liability matches, and liquidity concerns. Some funds would like the return over the liquidity, or vice versa. According to the nature of the assets and objectives, sovereign wealth funds' risk management can be extremely conservative to a high tolerance for risk-taking.