Compounding is when the interest on a sum of money, either a deposit or
loan, is added to the original amount so that the interest earned also earns
interest. Albert Einstein’s popular quote; ‘Compound interest is the eighth
wonder of the world. Those who understand it, earn it... those who don’t, pay
it’ highlights the impact compounding can have over time, and cautions that it
can work either for or against you.
“When you invest
in unit trusts, time allows your invested money to grow and
compounding makes your money work harder for you,” says Wanita Isaacs, investor education
manager at Allan Gray, an
independent African asset manager. “Given a long enough period to work,
compounding can dramatically multiply the value of your investment so that less
of your total investment will be from your contributions and more from investment
growth.”
While compounding
can be seen as the magic ingredient for successful investing, the same
mechanism works against you when you borrow money, for example, through credit
cards or a personal loan.
Isaacs explains
that the amount you owe earns interest over time and through the effect of
compounding, the cost of credit can work out to substantially more than the
cash amount you borrowed, depending on the interest you are charged and the
length of time you will be paying the loan back.
How does compounding actually work?
In summary, the
impact compounding will have on either an investment or a loan depends on:
·
The
amount invested or borrowed
·
The
time period
·
The
growth rate (the rate of return on an investment or the interest charged on a
loan)
·
The
compounding frequency (the more frequently interest is added to the original
amount, the greater the impact of compounding. For example, daily compounding
means that you earn returns today on the amount you invested, as well as the
returns you earned yesterday on the returns you earned the day before. This has
a greater impact than compounding monthly, which has a greater impact than
compounding annually.)
The table below
uses the example of an investment of US$10 000 and annual compounding to
illustrate how compounding works. “After 20 years, your US$10 000 investment
will grow to US$67 275 – a gain of US$57 275,” says Isaacs, adding that if your
returns had not been added to the original amount and left to grow; if you had
spent them instead, the total gain from your investment would only be US$20
000. “Since you would have spent this US$20 000, you would only have the
original US$10 000 still invested.”
Table 1: How compounding works
|
Amount of your investment
|
Return rate
|
Total amount with return earned
|
Year one
|
US$10 000
|
10% annually = US$1 000
|
US$11 000
|
Year two
|
US$11 000
|
10% annually = US$1 100
|
US$12 100
|
Year three
|
US$12 100
|
10% annually =US$1 210
|
US$13 310
|
How do you ensure compounding works for you?
To benefit from
compounding, you first have to start saving and the sooner you start the
better. “You also have to be disciplined and not spend the money your
investment makes before you reach your savings goal,” adds Isaacs.
The cliché that
good things come to those who wait is especially true when it comes to
compounding. Both the decision to invest and the decision whether or not to use
credit are essentially choices between instant and delayed gratification. “If
you choose to use credit you will have to pay for the benefit of instant
gratification whereas, if you choose to save, you will be rewarded for delaying
gratification,” Isaacs concludes.
Thandi joined Allan Gray in 2008. She is a senior
member of the distribution team having previously worked in legal and
compliance and marketing in the financial services sector. Thandi completed her
Masters of Business Law at the University of KwaZulu-Natal and is an admitted
attorney.