With a bond you would buy it for over face value (the dollar amount you receive when the bond matures), and the face value + interest received is less than what you paid for the bond (eg. you pay $101 for a $100 1 year bond at 0% interest which you hold until it matures: the bond yield is -1%).
With a bank account I assume they just take some percentage of the value of your account as a "fee".
With a bond you would buy it for over face value (the dollar amount you receive when the bond matures), and the face value + interest received is less than what you paid for the bond (eg. you pay $101 for a $100 1 year bond at 0% interest which you hold until it matures: the bond yield is -1%).
With a bank account I assume they just take some percentage of the value of your account as a "fee".