Fractional-reserve banking allows banks to provide credit, which represent immediate liquidity to depositors. The banks also provide longer-term loans to borrowers, and act as financial intermediaries for those funds. Less liquid forms of deposit (such as time deposits) or riskier classes of financial assets (such as equities or long-term bonds) may lock up a depositor's wealth for a period of time, making it unavailable for use on demand. This "borrowing short, lending long" or maturity transformation function of fractional-reserve banking is a role that, according to many economists, can be considered to be an important function of the commercial banking system.