CFA Society Cyprus’ Simon Kesterlian on Thursday set out the case for one of the most powerful ideas in personal finance, compound interest.

He asked a question many people may have seen online already. Would you rather have €1 million today, or a single cent that doubles every day for a month?

To illustrate the point, Kesterlian invited readers to consider two choices.

Dimitris takes the €1m today, while Sophia chooses a single cent that doubles every day for a month.

On Day 1, Dimitris has €1m, while Sophia has €0.01. “Pathetic,” as Kesterlian puts it. On Day 2, Dimitris still has €1m, while Sophia has €0.02. “Still pathetic.”  

By Day 5, Dimitris remains on €1m, while Sophia has €0.16, “not even close”.  

On Day 10, Dimitris still has €1m, while Sophia has €5.12.  

By Day 20, however, Sophia has €5,242.88, while on Day 25 that figure rises to €167,772.16.  

On Day 27, she reaches €1,342,177.28 and overtakes Dimitris. By Day 30, Dimitris still has €1m, while Sophia has €5,368,709.12. 

“This is the power of compound interest,” he said. 

Kesterlian then starts with the basics, explaining that when someone puts money in a savings account or invests it, they earn a return, typically expressed as an annual interest rate. There are, he said, two types of interest, simple and compounding. 

Simple interest, he explained, is straightforward: you earn a fixed percentage on your original sum every year. If you deposit €1,000 at 5 per cent simple interest, you earn €50 per year. After 10 years, you have €1,500. 

Compounding interest, however, works differently, and, as he put it, “far more powerfully”. Instead of earning interest only on the original €1,000, the investor also earns interest on the interest already accumulated.  

After year one, the amount rises to €1,050. In year two, the saver earns 5 per cent on €1,050, not just on €1,000, bringing the total to €1,102.50. The next year, interest is earned on €1,102.50, and so on. 

“The difference sounds small at first,” Kesterlian said. Over decades, however, he explained that it becomes extraordinary. 

For those who appreciate the mechanics, he sets out the core formula, FV = PV(1+r/n)ⁿᵗ* 

Where FV is the future value of the investment, PV is the principal or initial amount, r is the annual interest rate expressed as a decimal, n is the number of times interest compounds per year, and t is the number of years. 

The key takeaway, according to Kesterlian, is that the future value of an investment depends directly on four things: the initial amount invested, the annual interest rate, the number of times it compounds per year, and the number of years the investment is held. 

Of those four, he noted, time is the most important. 

To make that point more tangible, Kesterlian points to two investors, Andreas and Maria, both aged 25. Andreas invests €5,000 today and never adds another cent, earning a 7 per cent annual return. Maria waits 10 years, invests the same €5,000 at 35, and also earns 7 per cent. 

By the age of 65, Andreas’s €5,000 grows to approximately €74,872, while Maria’s grows to about €38,061. 

“Same amount invested. Same interest rate,” he said. A 10-year head start, he added, made Andreas nearly twice as wealthy. That, Kesterlian argued, is the power of time in compounding, and “the single most important lesson in this article”. 

He also offers a simple image to help readers visualise the idea: a snowball rolling down a hill. At the top, it is small. As it rolls, it picks up more snow. The bigger it gets, the more snow it collects with every rotation. By the bottom of the hill, what started as a handful of snow has become an enormous ball. 

Your money behaves in much the same way, he explained. The longer the hill, meaning the longer the investment horizon, the bigger the snowball.  

That is why, according to Kesterlian, financial professionals universally agree that starting early is the single most powerful action a young investor can take. 

He then turns to compounding frequency, noting that interest does not always compound once a year. It can compound annually, quarterly, monthly or daily. The more frequently interest compounds, the faster the money grows.  

Over many years, he said, the difference between annual and daily compounding on a large sum can amount to thousands of euros.  

For that reason, Kesterlian advises savers and investors to always ask how often a product compounds, because that single detail can materially affect the final outcome. 

Still, he warns that compound interest is “a double-edged sword”. 

If you are earning compound interest on an investment, he said, it works beautifully in your favour. If, however, you are paying compound interest on debt, such as a credit card balance, a personal loan or a consumer overdraft, it works just as powerfully against you. 

Kesterlian cites the example of a €3,000 credit card balance at an 18 per cent annual interest rate, compounded monthly. If only minimum payments are made, he said, that debt can take more than 10 years to clear and cost more than double the original sum in total interest payments. 

“This is why the same principle that builds wealth can destroy it,” he said. Understanding which side of compound interest you are on, he added, is one of the most important financial habits a person can develop. 

As a general rule, Kesterlian advises readers to eliminate high-interest debt first and only then redirect those payments into compounding investments. 

He also addresses why so many people fail to take full advantage of compound interest, arguing that the answer lies less in mathematics and more in human behaviour. 

First, he says, there is the difficulty of delayed gratification. Compounding rewards patience, yet people are naturally wired to prioritise the present over the future.  

Choosing to save or invest today often means giving up something tangible now for a benefit that feels distant and abstract. That trade-off, he explains, is psychologically difficult, especially when the early gains from compounding appear small and insignificant. 

Secondly, Kesterlian points to the tendency to underestimate exponential growth. Human intuition, he says, is linear, not exponential.  

People tend to think in straight lines, expecting steady and incremental progress, while compound interest grows slowly at first and then accelerates rapidly over time. As a result, many dismiss early investing efforts because the initial impact seems negligible, without realising that the most significant growth happens later. 

Thirdly, he refers to the illusion of “starting later”. A common belief, according to Kesterlian, is that investing can be delayed and made up for with larger contributions later on.  

While higher contributions do help, he notes that they rarely compensate fully for lost time. The early years of compounding are disproportionately valuable, and postponing them can significantly reduce long-term results. 

He also emphasises lifestyle inflation. As income increases, spending often rises alongside it. Instead of allocating additional earnings toward savings or investments, people may upgrade their lifestyle through larger homes, more frequent travel or higher day-to-day expenses.  

That, he says, reduces the capital available to benefit from compounding. 

Another barrier is interrupting the process. Compounding works best when left uninterrupted. Yet market volatility, short-term financial needs and emotional decision-making can lead people to withdraw investments prematurely.  

Even temporary interruptions, Kesterlian explains, can materially reduce long-term results, especially if they occur during periods of strong growth. 

Finally, he points to a lack of financial literacy. Many people, he says, simply do not fully understand how compound interest works. Without a clear grasp of its long-term impact, it is easy to underestimate the importance of starting early, contributing consistently and remaining invested. 

Turning to practical solutions, Kesterlian notes that in Cyprus and across Europe, young investors have access to several instruments where compounding works in their favour. 

The most accessible starting point, he says, is savings accounts and term deposits. Cypriot banks offer both savings and fixed-term deposit accounts and, although interest rates were historically modest, the current higher-rate environment across the eurozone has made these more attractive.  

He says readers should always confirm the compounding frequency, the fees involved and whether interest is reinvested automatically. 

He also points to investment funds and ETFs. Exchange-traded funds and mutual funds tracking broad market indices, such as the MSCI World or the S&P 500, allow returns to compound over time through price appreciation and dividend reinvestment.  

When dividends are reinvested instead of withdrawn, they buy additional shares, which then generate future returns. That, Kesterlian said, is compounding “in its most powerful form”. 

Retirement savings, including provident funds, are another important vehicle. Many employers in Cyprus offer provident funds and, especially where employers match contributions, workers are effectively receiving free money that also compounds over their working life. Those contributions, he suggests, should be maximised wherever possible. 

He also refers to stocks, noting that individual shares paying dividends offer the same reinvestment dynamic. A company that grows earnings year after year, with reinvested dividends, can deliver compounding returns over the long run. 

Regardless of the vehicle chosen, Kesterlian says three factors determine the scale of the outcome, time, rate of return and consistency. Time gives the investor more compounding periods. Higher returns accelerate growth.  

Meanwhile, regular contributions amplify the effect. Of those three, he stresses, time is the one that can never be recovered. 

He then turns to what he describes as one of the most persistent myths in personal finance, the idea that significant capital is needed to start building wealth. Compounding, he argues, demolishes that myth. 

Take someone investing just €100 per month from the age of 25, at an average annual return of 7 per cent. By the age of 45, that could grow to approximately €52,000. By 55, it could reach about €121,000. By 65, it could amount to roughly €263,000. 

The total amount actually invested would be €48,000. The rest, more than €215,000, would be, as Kesterlian puts it, “the pure result of compounding”. 

“Your money worked harder than you did,” he said. 

That, he argues, is accessible to virtually anyone. A daily coffee foregone, a monthly subscription cancelled, or a small portion of a paycheck redirected, these modest choices, sustained over time, can produce life-changing outcomes. 

No article on compounding, however, would be complete without addressing inflation. Kesterlian describes it as “the quiet force that erodes purchasing power over time”. If a savings account pays 2 per cent annually but inflation runs at 3 per cent, the real return is minus 1 per cent. In other words, the money is technically growing, but in practice it is losing purchasing power. 

“This is why simply keeping money in a low-yield savings account is not enough,” he said. For compound interest to work in your favour over the long term, returns must outpace inflation. Historically, diversified equity portfolios have done that, while cash deposits often have not. 

“Always think in terms of real, inflation-adjusted returns, not just nominal ones,” Kesterlian said. 

In the end, his message is straightforward. Compound interest is not a secret reserved for the wealthy or the financially sophisticated. Rather, it is “a mathematical certainty available to everyone”, and it rewards those who start early, stay consistent and remain patient. 

According to Kesterlian, the foundation of financial literacy rests on one principle: informed individuals make better financial decisions. Understanding compounding, he says, means understanding that time is your most valuable financial asset, and unlike money, it cannot be earned back once spent. 

Whether you are a recent graduate in Nicosia, a professional in Limassol or a parent thinking about your child’s future, the message, he says, is the same, “the best time to start was yesterday. The second-best time is today.” 

“Open that investment account. Set up that automatic monthly transfer. Let the snowball begin its journey down the hill,” Kesterlian said.  

“In 30 years, you will hardly remember the sacrifice, but you will absolutely feel the reward,” Kesterlian concluded.