what are some financial instruments that use compound interest 
most bank deposit accounts credit cards and some lines of credit will tend to use compound interest the bottom linesimple interest is the interest charge on borrowing that s calculated using an original principal amount only and an interest rate that never changes it does not involve compounding where borrowers end up paying interest on principal and interest that grows over multiple payment periods simple interest can be advantageous for borrowers because of its relatively lower cost of money however bear in mind that because of its simple calculation it gives only a basic idea of cost that may not account for other charges fees that a loan may include 