There are several ways to calculate the value of a security. The intrinsic value is the present value of expected future cash flows discounted at the required rate of return. Bonds provide interest payments and return of principal at maturity, while shares provide dividends and potential capital gains. The value of a bond is the present value of its interest payments and maturity value. Valuing stocks is more complex as cash flows are uncertain, but models like the dividend discount model can be used. Preferred stock is similar to valuing a perpetuity. Book value per share is calculated from a company's balance sheet but may differ from market price.