What If You Had Invested: The Power of Long-Term Investing

Imagine you have a time machine. You go back to the beginning of 2010, put a modest €1,000 into the broad US market — and immediately return to the present day, without touching anything in between. How much money is waiting for you?

The answer surprises almost everyone who hears it for the first time. This article tells what time does to money when you let it work — why a long horizon and compound interest, rather than skillfully guessing the "right moment," do the heavy lifting. You will see concrete historical numbers, we will compare them with an ordinary deposit, and we will say clearly how far they go — because the past explains the mechanism but does not promise the future. No "buy/sell" signals; just the mathematics and the honest caveats.

The time machine: a number that surprises

Let us start with the promised number. The S&P 500 index — a basket of the 500 largest US companies and the most commonly used gauge of the "broad market" — stood at about 1,074 points at the beginning of 2010 and close to 7,736 points at the beginning of 2026. That is a gain of more than seven times.

Applied to our hypothetical contribution, this means:

• You put in €1,000 in 2010.
• You do nothing more — you neither add, nor touch, nor sell in panic during the declines.
• By 2026 that money is about €7,203.

That is a total return of about +620% over 16 years, or an average of ≈ 13.1% a year. A single, one-time gesture in 2010 — and more than seven times the sum today, without a single additional decision along the way.

An important caveat right away: the number is historical and illustrative. We use it to show the mechanism, not because we expect it to repeat. This exact result is what the interactive "Time Machine" on the Selurio home page computes — you choose an asset, an amount, and a starting year, and it shows how your hypothetical contribution moves through the real historical values up to today. All the numbers below come from there; at the end we will show you how to replace them with your own.

The engine: time multiplied by compound interest

Where does this sevenfold difference come from? Not from luck with the exact day of purchase, but from two quiet mechanisms that work in tandem.

The first is compound interest: the return from one year becomes part of the capital on which you earn the next. The gains start generating gains of their own, and growth turns from linear into exponential. The second mechanism is time — and it is the more important one. In the mathematics of compounding, the number of years sits in the exponent, which is why every additional year weighs more than the previous one.

This is why the last few years of a long period bring the most: by then the accumulated sum is at its largest, and the same percentage return turns into the biggest absolute gains. The first €1,000 grows slowly and imperceptibly; only after it has become several thousand do the same percentages start adding hundreds at a time. Anyone who breaks off at exactly that moment deprives themselves of precisely the years in which the machine works hardest.

The mechanism and the formula are covered in detail in compound interest — the eighth wonder of the world, and you can compute it with your own assumptions in the compound interest calculator. And one more clarification, which we will repeat at the end: this ≈ 13.1% a year is the return of the specific window 2010–2026, which was unusually strong. The typical long-term average it is sensible to reckon with is more modest — a benchmark of around 7% is often used.

Market vs deposit at 2%

"All right, but money grows in a deposit too, doesn't it?" It grows — only at a completely different speed. The "Time Machine" compares each result with a deposit at 2% a year — a conservative but honest benchmark for a savings account. Here is how the same €1,000 contribution in the S&P 500 looks against such a deposit, for three different starting years:

Read the first row slowly: the same €1,000 from 2010 becomes about €7,203 in the market versus €1,373 in the deposit — more than 5 times as much. And that is not because the deposit is "bad": 2% a year simply cannot catch up with the long-term market return. The difference is not a few percent — it is a different order of growth.

The caveat holds in both directions. The deposit is predictable and almost risk-free, while the market can fall sharply in a bad year — which is why, for money you will need soon, the deposit is often the right choice. When each one is more suitable is the subject of deposit vs investing over 10 years.

Staying invested beats timing

The most common mistake of the new investor is not choosing the "wrong" asset, but trying to guess when to get in and out. The temptation is understandable: sell before the drop, buy at the bottom. The problem is that in practice almost no one manages to do this consistently — and the cost of the misses is brutal.

The reason is that the market's best days are clustered right around the worst ones. The big jumps up often come just days after the big falls, in the middle of the panic, when the temptation to be "out" is strongest. If you miss a handful of those days because you sold in fear, you cripple the entire long-term result.

Here is a typical illustration from widely published historical studies for a period of about 20 years. The numbers are rounded and show how much of the result is left compared with that of a person who was fully invested the whole time (100%):

Read directly: missing just 10 days over 20 years can cut the final result in half. The lesson is rare in its clarity — doing nothing, that is, staying invested for the whole period, historically beats attempts to jump the entry and the exit. This is exactly where the power of regular investing (DCA) lies: by putting money in at equal intervals, you automatically stay in the market and stop betting on timing.

Different assets, different paths

The S&P 500 is a convenient example because it is broad and representative. But the "Time Machine" lets you compare other assets too — and the differences are enormous. Here is what €1,000 invested once in 2010 would be worth in several of them:

Two things deserve attention. First, even among broad indices the difference is large — the technology-heavy Nasdaq outpaced the broad market over this specific period, but that same concentration in technology also brings sharper declines in the bad years. A higher return never comes for free — it is paid for with greater volatility along the way.

Second — and more important — here we deliberately show indices, not individual stocks. If you had guessed one specific winning company, the numbers look unreal: €1,000 in Apple shares in 2010 would today be more than €55,000. Except that this is a trick of hindsight called survivorship bias — today we see the surviving stars, but not the dozens of companies that went bankrupt, fell behind, or disappeared. No one knew in advance which they would be. That is exactly why the broad index, which holds everything at once, is the sensible starting point for most people: you do not bet on one horse, but on the whole team.

The past is not a promise of the future

Everything so far describes what happened, not what will happen. This distinction is the most important sentence in the article.

• The window was strong. 2010–2026 covers one of the best periods in the history of the market. Other 16-year stretches have returned far less, and some — almost nothing for a long time. That is why you should reckon with a modest benchmark (for example around 7%), not with 13%.
• The path is not a straight line. The average ≈ 13.1% a year hides heavy declines along the way — including years with double-digit falls. To "earn" that return meant staying in through the bad months too, not only the good ones.
• The numbers are "gross." The illustrations do not include fees, taxes, and currency differences, which reduce the real result. They also do not account for inflation — €7,203 after 16 years does not buy as much as the same sum today.
• It is not personal advice. Selurio is an educational platform, not a licensed financial adviser. Nothing here is a recommendation to buy a particular asset at a particular moment.

In other words: the past teaches us the mechanism — time plus compound interest, left uninterrupted — but it does not give us a schedule for future returns. It is sensible to expect less than this window and, for certain, to expect an uneven path.

Try your own time machine

The numbers in this article are only a few slices. The real value comes when you replace them with your own:

• Open the interactive "Time Machine" on the home page and choose your own asset, amount, and starting year — you will see the whole path up to today, compared with the deposit at 2%.
• For contributions forward in time (rather than backward) use the compound interest calculator: set a starting capital, a monthly contribution, and a horizon, and see how they grow over the years.

The goal is not to convince you that "the market always goes up" — it does not go up in a straight line and not every year is good. The goal is to feel what the real engine is: not the brilliant entry on the right day, but the patience to let time and compound interest do the work for you.

Sources

• Historical returns of stock indices — the long-term series of the S&P 500 and other broad indices are publicly available: a general reference to S&P Dow Jones Indices (opens in new tab).
• The numbers in the Selurio "Time Machine" are annual values, adjusted for dividends and splits (source: Yahoo Finance), updated monthly; the illustrations here use the data up to 2026.
• The illustrations of the "missed best days" summarize widely published historical studies by large asset managers; the specific percentages are rounded.

Historical returns vary greatly depending on the chosen period — past performance does not guarantee future results.

Continue reading

• Compound interest — the eighth wonder of the world — the engine behind long-term growth.
• DCA: why regular investing beats market timing — how to stay invested in practice.
• Deposit vs investing over 10 years — the same contribution in a deposit and at a market return.
• Compound interest calculator — compute your own scenario forward in time.

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