Most governments believe that their spending exceeds their income. As an alternative to unpopular tax increases, governments can raise money by selling government bonds, such as US government bonds. Government bonds are considered risk-free because the most stable governments are expected to not fail to meet these obligations. These debt instruments are more popular in times when stock markets look weak, while timid investors look for safer options. Another way to invest in debt instruments and government bonds is through derivatives, such as futures and options. (For related information, see Six largest bond risks.)