The relative percentages of core asset classes such as equities, fixed income and cash, along with real estate and international holdings, found within a mutual fund, exchange-traded fund or other portfolio. Further breakdowns are sometimes made within the asset classes into growth stocks, value stocks, market capitalizations (small, medium, large) and various types of fixed income such as government bonds, corporate bonds and municipal bonds.

Asset class breakdowns are calculated by dividing the market value of a particular asset class's holdings by the total fund or portfolio assets.

The asset class breakdown is a simple way to determine the approximate risk profile of a fund. Higher equities exposure equates to a higher potential return, but with greater risk than a portfolio made up of mostly bonds. Many analysts and economists feel that proper asset allocation is the biggest determinant of overall returns - far greater than sector selection or individual security selection.