Why you should invest: you become part-owner of thousands of real companies

A broad global index fund makes you a small owner of thousands of real businesses, and what those businesses earn is what ends up as your return. That is a very different thing from betting that a chart keeps going up.

What you actually own

Buying a broad world ETF makes you part-owner of companies you already deal with every week. The Apple or Samsung phone in your pocket, whose chips are made on ASML machines. The Lotus speculoos you pick up at Colruyt. The software Microsoft sells to your employer. Index investing means buying a slice of everything, spread across as many companies, countries and sectors as possible.

You do not have to know which company will beat the market next year. You do not have to decide whether Europe, the United States, China, technology or healthcare is the better bet. You buy all of it, which makes this way of investing calmer as well as simpler.

What that has been worth

The MSCI All Country World Investable Market index has returned an average of 8.2% a year since 1994. It holds more than 8,000 companies across over 40 countries, and the SPDR MSCI ACWI IMI ETF tracks it, so a single fund gets you close to the whole listed world economy.

That 8.2% did not arrive in a straight line. 1999 was a spectacular year and 2000, 2001 and 2002 were brutal ones. The chart below comes from Backtest, our free tool for checking how an index has actually performed, so you can look at the bad years yourself rather than take our word for the average.

Your return comes from what the companies earn

Your return comes from company profits. As a shareholder you own part of a business, and that business tries to earn more every year.

Take a simple example. You buy a share for €100 and the company earns €5.50 per share that year. That is an earnings yield of 5.5%. You get to the same number by flipping the price-to-earnings ratio, which tells you how many times a company's yearly profit is contained in its share price. A price-to-earnings ratio of 18 works out at 1/18, or roughly 5.5%. Whether the company pays that profit out as a dividend or reinvests it in the business matters less than most people think, because you benefit either way.

History has been generous to shareholders. J.P. Morgan Asset Management's Guide to the Markets puts the real return of US shares at 6.9% a year between 1900 and 2025, after inflation. Those decades were unusually good, so we would rather plan with more conservative expectations than assume they repeat.

Companies keep trying to earn more, and that is the bet

The bet you are making is that companies keep trying to earn more, and that over long periods most of them succeed. The baker in your village is working on better pastries. Supermarkets are looking for ways to bring in more customers. Restaurants change their menus for new tastes, and hotels improve their service to get better reviews. Across the economy, business owners improve products, cut costs and look for new customers.

Listed companies do the same at a much larger scale. Today that happens with artificial intelligence, tomorrow with something else. Over long periods, companies have kept finding ways to become more productive and create more value, and a global index fund is how an ordinary investor shares in that.

One company going under barely moves your portfolio

When one company inside a global ETF collapses, you barely notice. Lernout & Hauspie went down in 2001 after accounting fraud, General Motors filed for bankruptcy in 2009, and Kodak followed in 2012 once digital photography had taken its market. Anyone who owned only those shares lost almost everything. Anyone holding a global ETF saw a rounding error.

That is company-specific risk, and diversification removes it. What stays is market risk: the chance that the whole market falls at once because of a recession, a pandemic, a war or a financial crisis. You cannot diversify that away, and it is also the risk you are paid to carry.

Investing is how you keep your purchasing power

A Belgian savings account has paid less than inflation in most months since 2003, so money left there loses purchasing power year after year. Nothing on your statement shows it happening.

€1,000 from 1995 buys about €511 worth of goods today. Almost half the purchasing power is gone, and it went without a single dramatic day.

Between 2003 and 2025, Belgian inflation averaged 2.45% a year while the average savings rate was 0.83%. Inflation was higher than the savings rate in 84% of those months. Statbel publishes the Belgian consumer price index and the ECB publishes what banks pay on deposits, so both series are there to check. When the war in Ukraine began in 2022, Belgian inflation climbed above 12% while savings rates followed slowly.

Shares have beaten inflation over long periods for two reasons. Investors want to be paid for the risk they take, which is called the risk premium. And companies grow with the economy: they pass rising costs into their prices, develop new products and become more productive, so profits at successful companies tend to rise faster than prices do.

Leaving your money alone is a decision with its own risk. €10,000 stays €10,000 on your screen while it buys less every year. The hidden risk of saving is that the money does not grow enough to reach your goal. We look at the impact of inflation on a Belgian savings account in more depth.

What €100 a month becomes

Two friends who put aside exactly the same €100 a month since 1999 ended up three and a half times apart, and the difference came from where the money sat.

Sara and Imani both started saving for retirement in 1999, €100 every month. Sara had never been taught anything about investing, so her money went to a savings account, month after month. Imani put the same €100 each month into a single broad world ETF. Both have now paid in €32,800. Sara's savings account grew with modest interest to roughly €36,000. Imani's portfolio grew to almost €130,000. The figures come from our Backtest tool and ECB savings rate data.

Imani did not work harder or save more. She put an identical amount of money to work in a different place, and a long horizon did the rest.

Why the gap gets so wide: growth on growth

The gap widens because your returns start earning returns of their own. Invest €100 at 10% a year and you have €110 after one year. The next year you earn 10% on €110 rather than on €100, so you gain €11 instead of €10 and end at €121. The year after that you gain €12.10.

Leave that €100 alone for forty years and it grows to €4,526. In year 40 by itself, the investment earns €411. That single year produces more than the €380 the whole investment was worth after fourteen years. This is compound interest, and it works like a snowball rolling downhill: slow at the start, then picking up more with every turn.

No investment delivers a tidy 10% every year, so read this as arithmetic rather than a forecast. Higher expected returns always come with bigger swings along the way. What matters more than the percentage is the monthly investment amount you can genuinely keep up for decades.

Wealth gives you options

The point of building wealth is choice. With enough financial room you can work less while your children are small, turn down a job that pays well and drains you, bridge a few months while you change direction as a freelancer, or pay for a course. Financial freedom is mostly about having more say over your own time.

You do not need a precise goal to start, especially when you are young. You probably do not know where you will live in five years, what job you will have, or what your family will look like. Life brings a new job, a child, a divorce, an illness, a parent who needs care, a partner who wants to work less. Wealth gives you options when those arrive.

Freedom depends on the gap between what comes in and what goes out, not on the salary. Someone earning €10,000 a month and spending €9,500 has less room to move than someone earning €3,000 and spending €1,500. The second person builds a buffer faster and needs less to live comfortably.

A portfolio is not an emergency fund. Money for unexpected costs in the next few months belongs in a savings account. Long-term wealth is what makes you resilient when your life changes direction.

What investing actually costs you

The cost of investing has a number attached to it. After the dotcom peak in August 2000, a global portfolio more than halved, and the market needed 12.5 years to reach that high again.

The dotcom crash, in euros and in years

Here is what the dotcom crash did to someone investing €200 a month. Say you started in August 1990. By the market peak in August 2000 you had paid in €24,200 and your portfolio was worth roughly €71,000. Then the crash came, and by March 2003 your portfolio was down to about €37,000, even though you had by then paid in €30,400.

You kept investing €200 a month. By December 2005 your portfolio was back at €71,000. It took you a little over five years to recover, while the market itself needed 12.5 years to reach its 2000 high. Buying at lower prices during the fall is what closed the gap.

A year later the financial crisis hit and your portfolio dropped again, to around €47,500 in February 2009. You kept going. When the market finally reclaimed its 2000 peak in March 2013, your portfolio had already grown to about €114,000. All of these figures come from our Backtest tool.

The market's recovery time and your recovery time are two different numbers when you keep buying every month.

Your odds of a loss shrink as your horizon grows

How long you stay invested changes your odds more than anything else you control. Take the MSCI World index, roughly 1,500 companies from developed markets like the United States, Germany, Japan and the United Kingdom, with data going back to 1970.

Someone who bought at a random moment between 1970 and today and sold exactly one year later ended up with a loss about 26% of the time. That is frightening, and it should be, if you need the money after a year. Over five-year periods the chance of a loss fell to about 17%. Over twenty-year periods there is no starting date in the whole history of the index that ended in a loss.

Even someone who started at the absolute dotcom peak in March 2000, right before a fall of more than 40% and a financial crisis seven years later, was ahead twenty years on. These numbers are for someone who invested everything at a single moment, and spreading your purchases over time improves them.

Volatility is the price you pay for the return

Volatility is what a stock market return costs, and the two cannot be separated. A fine is what you pay for having done something wrong, so you try to avoid it and feel hard done by when it lands. A price is what you pay to get access to something you want. The entrance fee at a theme park is not a punishment, and once you are inside, nobody leaves the rollercoaster because the car dips.

Shares return more than a savings account precisely because they move around. A market that rose a tidy 8% every year without a wobble would be the suspicious one, because there would be no reason for it to pay more than a government bond. The uncertainty is the source of the return.

None of that makes a falling portfolio pleasant, and experienced investors do not enjoy it either. It does help to read a drop as the bill that comes with what you are trying to achieve. We go through the risks of investing and which of them are worth taking, and if the fear of losing money is what keeps you on the sidelines, that is worth working through before you start.

Investing this way is boring, and you will never own the best-performing thing

Passive investing is dull by design, and the dullness is part of what it costs you. You buy a broad portfolio, you keep it, and you do very little. Nobody at a dinner party is impressed by someone who just follows the market.

You will also never hold the best investment of the moment. There will always be a share, a sector, a cryptocurrency, a property project or a themed ETF doing far better than your portfolio for a while. Buying the whole market means accepting the average of it.

You fall with the market too. Diversification protects you from one company failing, not from a general crash. Anyone who cannot live with a portfolio that temporarily drops 20% or 30% should hold fewer shares.

The last cost is psychological. This way of investing needs little knowledge to start and a lot of character to keep going. Doing nothing sounds easy until everyone around you starts saying you should do something.

Fees are the cost you control

Fees are the one part of your return you decide. You cannot know what the market will do next year or which sector will lead it. You can choose how much you are willing to pay to be there.

The arithmetic is unforgiving. A fund charging 1.5% a year more than a comparable ETF has to beat that ETF by 1.5% every single year just to finish level, and most active funds do not manage it. Traditional funds from banks, insurers and private banks carry those higher yearly costs. They rarely stand out on your statement, but they leave your return every year all the same.

Three layers sit between the market's return and yours. The fund provider charges a yearly fee, called the total expense ratio, and the costs of an ETF are usually a small fraction of what a bank fund charges. Your broker may charge for transactions. And taxes take their share. What is left after all three is your net return, which is the only number that ends up in your account.

When you should not invest

Investing is the wrong answer in four situations, and they come in a fixed order. Think of your finances as a waterfall: money only flows down to the next level once the level above it is full.

Pay off expensive debt first

Expensive debt beats any investment you can make. We do not mean your mortgage. We mean an outstanding credit card balance or a consumer loan, where the interest rate is high.

Take a credit card charging 15% a year. Every euro you use to pay that balance down earns you a guaranteed 15%. No global equity portfolio can promise you that.

Build an emergency fund before you invest

Invest only money you will not need in the short term, and an emergency fund is what makes that possible. Picture €10,000 saved and enthusiastically invested. A few months later the market drops 30% and your boiler dies. The repair costs €3,500. With no cash left, you have to sell part of your ETFs at a loss, so you take an unexpected bill and a forced sale at the worst possible moment in the same week.

An emergency fund is money you keep aside for the unexpected: a broken car, an urgent repair at home, a medical bill. It is not the same as saving for a specific plan. Money for a car, a renovation or a trip is a savings goal. Mixing the two up makes the buffer feel like it is never big enough.

How much goes to saving or investing deserves its own answer, and so does where the buffer should sit, because Belgian savings accounts pay very different rates.

Money you need within a few years does not belong in shares

Money you need within a few years should stay out of an equity ETF. A question we hear often comes from someone buying a house in two years whose money is sitting at the bank doing nothing. Markets can fall sharply and a bad stretch can drag on for years. If the date arrives in the middle of one, you may have to sell at a loss.

Savings accounts, term accounts and short-dated bond ETFs suit short horizons better. They pay less than shares over the long run, and safety is what you want when the date is close.

Your goal sets your horizon, and your horizon sets how much risk you can take. A 10% fall when you are 25 years from retirement is annoying. The same fall two years before you buy a house is a real problem.

If a 30% drop would make you sell, the portfolio is wrong for you

A portfolio that makes you sell in a panic is the wrong portfolio for you, however good it looks on paper. Three questions decide how much risk fits. When do you need the money, which is your investment horizon. How much risk can you carry financially, which depends on your income, expenses, savings, debts and buffer. And how much risk can you handle emotionally, which is your risk tolerance and has more to do with character than with knowledge.

Those three rarely line up neatly, and when they disagree you follow the most restrictive one.

The most useful question to ask yourself is what you would do if your portfolio fell 30% tomorrow. Nobody predicts their own feelings perfectly, but the question forces you to be honest. Selling during a fall turns a temporary loss into a permanent one, and usually costs you the recovery that follows.

One more case belongs here. If what you enjoy is analysing companies and following markets, buying the whole market and then doing nothing may simply be too boring for you, and there is nothing wrong with that.

Once those are handled, starting beats optimising

Once your debts, your buffer and your horizon are in order, starting matters far more than getting every detail right. Plenty of people quietly use their emergency fund as the reason never to begin, and two, three or four years go by with the same sentence: still building my buffer.

An emergency fund is a fixed target with an end point. Once you reach it you can stop saving for it and start investing. You do not even have to wait for it to be complete. If you are most of the way there, split your monthly saving so that part goes to the buffer and part goes to your investments.

There is a difference between rational and reasonable. Rational is what the maths says is optimal. Reasonable is what a person who is not a calculator will actually keep doing, and in investing, keeping going beats being optimal. The highest return, the lowest fee and the best broker all matter less than starting and continuing, which is why waiting for the right time to start is the most expensive form of optimising there is.

The bottom line on why you should invest

You invest because a broad global index fund makes you a part-owner of thousands of companies that spend every day trying to earn more, and because that is the most realistic way to protect the purchasing power of money you will not touch for decades. The falls along the way are the reason the return exists in the first place.

The alternative is not a risk-free one. Leaving everything on a savings account swaps a visible risk for a slow one that only shows up thirty years later, when the balance is intact and buys far less than you needed it to.

So start with your own reason and your own horizon rather than with a fund. Then clear the prerequisites: expensive debt paid off, an emergency fund in place, short-term money kept out of shares, and a portfolio you would not sell in a 30% drop. Once those are done, keep it simple and keep going. With Curvo you can set up a monthly plan in a few minutes and let it run.