APY is short for annual percentage yield. The APY is the actual rate of interest paid, or earned, during a year, with compounding. APY is in contrast to APR, or annual percentage rate, that is usually advertised. For example, a bank advertising a 3-month CD with an APR of 5.00% would have an APY that's higher, due to compounding. If the 3-month CD were rolled over four times in the year, the APY would equal 5.00% divided by 4 and then compounded over 4 periods, which would equate to an APY of 5.09% (1.0125^4-1=5.09%). So if you purchased a CD with an APY of 5.09%, on January 1st for $10,000 and rolled it over 4 times, your balance at the end of the year will be $10,509.45, not $10,500.00. |