ETF vs index fund: which should you choose?
An ETF and a traditional index fund can offer an investor a very similar investment. Both can track, for example, the S&P 500 index or the global equity market. In that case, the difference lies not so much in what they invest in as in how the fund units are bought and sold and what costs the investment involves.
An ETF can be an interesting option especially when you invest in larger amounts or want to make use of a wide international range of funds. The advantages of a traditional index fund, on the other hand, can include small subscription amounts and effortless monthly saving. However, neither is automatically cheaper or better-performing than the other.
Index-tracking ETFs and traditional index funds are popular ways to implement a passive investment strategy. The idea of passive investing is to track the performance of a chosen market index instead of actively picking individual stocks. Read more about the basics of index investing.
What do ETFs and index funds have in common?
Let's start with the common ground: what do an ETF and an index fund have in common?
An ETF and a traditional index fund can track the same market index and offer an investor very similar diversification. For example, an ETF tracking the S&P 500 index and an equivalent traditional index fund invest, in principle, in the same large US companies. Both aim to track the performance of the index as closely as possible, allowing for costs.
An ETF (exchange-traded fund) is a fund whose units can be bought and sold on a stock exchange in the same way as shares. Many ETFs passively track a specific market index, but actively managed ETFs are also available. Read more about .
A traditional index fund, on the other hand, invests by tracking a chosen market index, but its units are not bought on a stock exchange. Fund units are subscribed and redeemed through the fund management company or an investment service provider at a value determined in accordance with the fund rules.
So an ETF can also be an index fund. In this comparison, we focus on index-tracking ETFs and traditional index funds. The key differences between them relate to trading, costs and investing in practice. In both cases, you own a share of the fund's assets. The “wrapper” is different, but the idea is the same: you invest in the whole index with a single product.
“So an ETF and an index fund are like two different routes to the same destination.”
Why both are an investor's friends
Passive index-tracking ETFs and traditional index funds give investors the opportunity to benefit from market performance without constantly picking individual stocks. The advantages of both include the ability to diversify your investments, often moderate costs and features suited to long-term investing.
Passive investing: In index-tracking ETFs and traditional index funds, the holdings are determined by the rules of the chosen index (e.g. the S&P 500 or OMXH25). The aim is not to beat the index's return through active stock picking, but to track its performance as closely as possible. This can keep the funds' management fees low, although costs vary from product to product. Read more about indices.
Diversification: With a single purchase, you get a slice of hundreds or even thousands of companies across several sectors and geographical regions. Even a small monthly amount gives you access to a broad market without having to build diversification one stock at a time.
The compounding effect: When the income the fund receives is reinvested, it can increase the capital on which future returns are based. Low costs leave a larger share of any return to the investor.
Ease of use: Both ETFs and index funds can be bought regularly without constantly following the markets. With index funds, monthly saving is usually fully automatic. With many brokers, monthly saving in ETFs is possible through an automatic plan or, alternatively, through recurring purchases.
What sets an ETF and an index fund apart?
Although ETFs and index funds go hand in hand in many respects, how they work in practice and what they are like to use differ like night and day. Here are the key differences, from where you buy to the rhythm of trading, and from liquidity to the cost structure:
1. Where you buy and the rhythm of trading
Units in a traditional index fund are bought and sold through the fund management company or an investment service provider. The price of a fund unit is based on the value calculated in accordance with the fund rules, known as the NAV (net asset value). The trade is not executed at a real-time exchange price, and the exact execution price is usually not known when the order is placed. A subscription or redemption may take one or more banking days to complete.
An ETF, by contrast, is traded during stock exchange opening hours in the same way as shares. Its market price fluctuates during the trading day based on supply and demand. An investor can, for example, use a limit order to set the highest acceptable purchase price or the lowest acceptable selling price. The trade is executed when there is a counterparty in the market that meets the terms of the order.
The advantage of an ETF is the ability to influence when you trade, whereas with a traditional index fund the investor does not need to follow intraday price movements.
In other words, an index fund is like a train that leaves the station once a day on schedule: you can get on board, but you do not decide the speed. An ETF is like your own car, which you can set off in whenever you want.
2. Liquidity and getting your money out
ETF units can usually be sold during stock exchange opening hours, and the trade can be executed quickly if there is enough demand in the market. However, the execution of a sell order does not mean that the money can be withdrawn to your bank account straight away. Settlement of the trade and the transfer of funds can take time.
Redemptions from a traditional index fund take place according to a schedule set by the fund management company. The redemption price is based on the value calculated in accordance with the fund rules, and the exact execution price is usually not known when the order is placed. It can take several banking days for the money to be paid into your account.
An ETF offers more flexibility in choosing when to sell, but how smoothly trading goes also depends on the fund's liquidity and market conditions. For a long-term investor, a difference of a few days in access to funds is not necessarily decisive, but it is worth taking into account when assessing how much liquidity your investments need.
3. ETF and index fund costs
Costs get talked about because they matter. The ongoing charges of index-tracking ETFs and traditional index funds are often moderate, but they vary from fund to fund. Some ETFs have ongoing charges of only 0.03% a year. However, an ETF is not automatically cheaper than an equivalent traditional index fund, because the total cost is also affected by the provider's price list, the amount invested and how often you buy.
A brokerage fee is usually charged for buying and selling an ETF, and its size depends on the provider and the service used. The fee can be, for example, a fixed amount in euros or a percentage of the trade value. Costs are also affected by the spread, or bid-ask spread, meaning the difference between the buy and sell price, which is usually small for liquid ETFs. Currency exchange can generate costs if trading requires converting currency.
With most providers, index funds have no purchase or sales fees at all, so for someone investing small amounts frequently and regularly, an index fund can work out cheaper, unless the ETF is bought through a fee-free monthly savings plan.
In summary: with index funds, costs are easy to predict (only the management fee, often below 0.5%), whereas with an ETF the total cost is made up of the management fee plus trading fees and any spread. With larger lump sums and less frequent purchases, the ETF's cost advantage comes into its own.
Example of ETF trading fees
Let's assume the brokerage fee for an ETF purchase is €5. The fee's relative share then depends on the amount invested:
- On a €100 purchase, the fee equals 5% of the amount invested.
- On a €1,000 purchase, the fee equals 0.5% of the amount invested.
Example of index fund costs
Let's assume the index fund's ongoing charge is 0.30% a year and no subscription fee is charged. The charge is not paid separately but is deducted from the fund's value:
- On an investment of €10,000, the charge is around €30 a year.
- With monthly saving of €100, the charge in the first year is around €2, because on average €650 is held in the fund over the year.
If the same monthly purchases were made in an ETF with a €5 brokerage fee, the fees would add up to €60 a year. With a lump-sum investment, the fee is paid only once, so the ongoing charge becomes more significant.
Small monthly amounts put an ETF at a disadvantage unless you use a cost-efficient savings plan or buy less often. So look at the big picture, not just one row of the table.
4. Range and availability
The range of ETFs is wide and international. It includes, for example, funds tracking global equity indices, ETFs focused on specific sectors, fixed-income funds and options based on various investment strategies. An ETF can also offer a way to invest in markets that you may not be able to access through traditional index funds.
The range of traditional index funds often focuses on well-known market indices, such as the global, European and US equity markets. A range like this can be quite enough for an investor who is looking for broad diversification without needing to invest in individual sectors or narrowly defined investment themes.
However, not all exchange-traded investment products are ETFs. For example, products linked to a single precious metal that track the price of gold or silver are typically ETCs in Europe. Their structure and risks differ from those of ordinary ETFs.
Read more about .
5. Ease of use and practicalities
Index funds shine in their simplicity. Owning an index fund does not require you to keep track of stock exchange opening hours, time your orders or set limit prices. You switch on monthly saving and it simply happens.
Another practical difference is the minimum amount: with traditional index funds, you can usually invest whatever amount in euros you like, within the fund's minimum subscription. Fund units are available in fractions, so an investment of, for example, €25.50 may be possible. ETFs are usually bought as whole units. If one ETF unit costs €50, the amount you invest must then be at least €50, plus trading fees. However, some providers also allow you to buy fractions of selected ETFs, in which case buying half a unit, for example, may be possible. It is worth checking how this works with your own service. With small monthly amounts, a traditional index fund can be the more flexible option if fractional ETF units are not available.
6. Taxation
In Finland, ETFs and traditional index funds are taxed largely on the same principles. Gains from selling fund units are, as a rule, taxable capital income, and any capital losses are deductible in accordance with tax legislation.
An important difference for tax purposes is whether the fund distributes income to the investor or reinvests the income it receives within the fund. Both accumulation and distribution units are available for both types of fund.
With accumulation units (accumulating), the income the fund receives remains part of the fund's assets. In this case, the investor does not usually incur personal tax on income reinvested within the fund. Any capital gain is taxed only when the fund units are sold.
With distribution units (distributing), the fund instead pays part of its income to the investor. The distributed income is, as a rule, taxable capital income in the year it is paid. Income distributed by a fund should not be confused with a dividend received directly from a limited company, as they are treated differently for tax purposes.
The tax advantage of accumulation units relates to the timing of taxation. When the fund's income is reinvested rather than paid out to the investor, personal taxation is deferred until any capital gain is realised. This can support the compounding effect over the long term, as no tax has to be paid each year on income paid out to the investor. However, an accumulation unit is not automatically a better option than a distribution unit: the choice also depends on the investor's goals and the fund's other features.
In 2026, the capital income tax rate in Finland is 30% up to €30,000 and 34% on the portion above this threshold. When fund units are sold, tax is, as a rule, paid on the capital gain, not on the full sale proceeds. Any capital losses, in turn, can be deducted in taxation under the applicable rules.
So, on taxation alone, there is no decisive difference between an ETF and a traditional index fund. With both, it is worth looking at how the fund handles income, what it invests in and the total costs.
Read more about the taxation of investments and the taxation of funds.
7. Summary: ETF vs index fund
Use cases: which one suits which situation?
It is time to put what we have learned into practice. In what kinds of situations do ETFs and index funds fit most naturally? Below are a few example profiles and situations. Perhaps you will recognise yourself in one of them.
1. The monthly saver who is just starting out
You want a simple, automatic solution. This is what an index fund is made for: set the amount and let the process take care of the rest. You can set up a monthly savings agreement with your broker, so that €50 goes automatically into, say, a global index fund every month. You do not need to follow the stock market or think about when to buy. The index fund takes care of diversification and updates in the background while you get on with everyday life. An ETF also suits a beginner, but then you have to do a little more yourself. In addition, investing very small amounts can also be frustrating if every purchase costs a few euros in brokerage fees.
2. The experienced diversifier and big saver
You already have investing experience and are interested in diversifying your assets broadly across different asset classes. Perhaps, in addition to equities, you want to hold fixed income, emerging markets or even gold.
An ETF gives you a toolkit for putting almost any investment idea into practice. You can pick ETFs from around the world and from different sectors for your portfolio and build a very broadly diversified whole. Because you invest larger sums at a time, the low costs of ETFs come to the fore: over the long run, you save more money on management fees compared with more expensive funds. In addition, brokerage fees stay moderate relative to the amount invested. An experienced investor can also make use of the flexibility of ETFs, for example to reduce portfolio risk by quickly selling a particular ETF if a market is in turmoil, or to buy more on a dip.
3. The cost optimiser
You are very cost-conscious and want to minimise all the costs of investing. Perhaps you enjoy shaving tenths of a percentage point off the cost structure, because you know that over the long term small differences in costs can mean thousands of euros more in returns. For an investor like this, an ETF is often attractive, as at best the costs of ETFs can be less than half those of an equivalent index fund. For example, if a domestic index fund costs 0.30% and an equivalent ETF 0.07%, the ETF wins the cost contest.
But remember to factor in trading fees! If, for example, you invest a larger sum in an ETF once a year, costs stay very low. If, however, you want to invest small amounts every week, an index fund may surprisingly be the cheaper option, unless you use an ETF monthly savings service. So it makes sense to choose an ETF or an index fund based on which one actually works out cheaper for the way you invest, and often to combine both (e.g. monthly saving in an index fund, with additional investments in ETFs as larger lump sums).
4. The investor with specific needs
In certain situations, an ETF may be the only option or a clearly better one. For example, if you want to invest in a specific theme (such as renewable energy, artificial intelligence or healthcare) or a more exotic market (such as Asia's growing economies), a ready-made, precisely targeted and cost-efficient index fund may not be available to you, but there will be an ETF. In the world of ETFs, there is a fund for almost every purpose.
You can also invest in the price performance of gold and silver through ETCs traded on a stock exchange. In Europe, exchange-traded products backed by physical gold or silver are typically ETCs, whose structure and risks differ from those of ETFs. Read more about .
The situations above are not rules set in stone, but they give a feel for which instrument typically fits which need better. Next, we consider whether you could use both at the same time, because many investors find that ETFs and index funds complement each other rather than rule each other out.
Combination tactics: how to use both in your portfolio
The contrast between them is often emphasised, but in reality an ETF and an index fund can live in perfect harmony in the same portfolio. More experienced investors often use both tools for different purposes. Here are a few ways to combine the best of both:
1. A core of index funds, with ETFs to complement it: One sensible strategy is to build the core of your portfolio from a few broad index funds, for example a global equity index fund and perhaps an emerging markets index fund, which you add to automatically every month. This ensures that most of your assets are diversified easily and with discipline.
Alongside this core, you can use ETFs to pick targeted diversification or specific themes: for example, add a US small-cap ETF, a little exposure to European corporate bonds through an ETF, or perhaps a real estate ETF to give the portfolio a dash of property. ETFs also let you respond to situations: if you see an opportunity in the market (e.g. the oil price collapses and you want to bet on oil companies), there is probably an ETF you can buy into your portfolio temporarily. Index funds do not offer this kind of agility, so an ETF complements the portfolio by giving you the freedom to “step off the path” when needed, as long as you do it with care.
2. Adjusting over your life cycle: For a young investor who is just starting out, index funds can be a great way to get going without any extra fiddling. As experience grows, many move partly into ETFs to benefit from the wider range and lower costs. There is nothing wrong with this: learning and interest take you deeper, and that is when the world of ETFs beckons. Others do the opposite: as age and wealth accumulate and you want to simplify life, you may go back to using mainly index funds and cut down on active trading. So you can adapt how you manage your portfolio to your life situation and interests. You do not have to commit to either one for life, and you can also hold both side by side. For example, you can keep your long-term investments growing tax-efficiently in index funds while “playing” with a small pot of play money in ETFs if you want to try out ideas.
3. Tax planning with two tools: The combination also gives you flexibility for tax purposes. For example, if at some point you want to realise some of your gains for your own use, you can consider whether to sell index fund units or ETFs based on which one has fewer tax consequences or costs. If one has a large built-in gain and the other less, the choice may fall on the other. Likewise, you can spread sales of both instruments over different years if needed. These are matters of fine-tuning, but they can bring an advantage for a more advanced investor.
The message of these combination tactics is that ETFs and index funds are not enemies. They are tools you are free to use side by side. The most important thing is that your investment plan is clear: you know why you use each one and you avoid unnecessary overlap. With both, you can build, if you wish, a well-diversified, low-cost portfolio that follows a path in line with your goals.
Common mistakes and misconceptions
Mistakes are sometimes made along the investing journey; that is part of learning. Here are some common misconceptions and pitfalls related to ETFs and index funds, so that you can avoid them:
1. “An ETF is always better because the costs are lower.”
Costs matter, but they are only one part of the picture. It is true that the most efficient ETFs can cut costs to as little as half those of a good index fund, but if you pay fees to buy or make hasty moves, you may not benefit from the 0.2% saved after all. In addition, it is frustrating for a beginner to try to over-optimise: it is more important to start investing at all than to chase the very lowest cost. Do not let the “0.1% vs 0.2%” debate stop you from getting started. Both options are very low-cost compared with many other investment products.
2. Rushing to sell your funds to switch to ETFs
Many people start with index funds and later discover the advantages of ETFs. It is then tempting to sell all your fund units and switch to ETFs in one go. If your index funds are showing a gain, this is usually a mistake: you trigger tax unnecessarily, which eats up a large part of the benefit. For example, paying 30% tax on your gains is a much bigger one-off cost than paying a slightly higher ongoing charge in the fund. A smarter approach may be to direct new savings into ETFs and let your existing fund holdings continue to grow.
3. Accidentally diversifying too narrowly
One misconception is: “I bought an index fund, so my diversification is in order.” Not automatically. The question is: which index is the fund tied to? If, in practice, your money is in a single Finland index fund, you mainly own a small group of the largest companies on the Helsinki Stock Exchange, with heavy weights. That is diversification within the home market, but not yet geographical, currency or sector diversification.
Similarly, in the vast sea of ETFs, you may end up buying several overlapping ETFs thinking you are diversifying, while without realising it you own the same Nvidia and Apple shares in several different funds.
The solution: read what the fund holds and understand the index. Diversification is a great thing, but it only works if the index is broad enough and the investments are spread across different holdings. A typical mistake is to start investing with, say, just a technology sector ETF, thinking it is “the whole world index”. In that case, the portfolio is only a narrow slice of the market. Read more about the different types of index.
4. Actively trading ETFs in a long-term strategy
The fact that you can buy and sell an ETF throughout the day does not mean you should. Real-time trading is a handy feature, but it is also a door through which a passive investor can slip, without noticing, into becoming an active speculator. Many find that a “small move” turns into a habit, and the habit turns into costs, tax consequences and scattered decision-making. The combined effect eats into returns.
Stick to your strategy. If the aim is to save in an index over the long term, use an ETF's flexibility only when it genuinely makes sense: for example, rebalance your portfolio once a year, not once a day. As the old saying goes, “Time in the market beats timing the market”, meaning that time spent in the market beats attempts to time the market. An ETF does not make you any better at forecasting the market, so avoid excessive trading.
5. Getting stuck in analysis paralysis
One of the most common mistakes is to spend months or even years pondering which is the “right” choice, “ETF or index fund”, and not getting started in the meantime. Meanwhile, the market has time to deliver its returns, and you miss out on them. The truth is that both are good options. If you dither for too long, you lose valuable time that could have been invested. Better to start with either one today than with the perfect instrument only tomorrow. You can always fine-tune along the way.
The most important thing is that you invest
Our story of ETFs and index funds could be compared to two travellers. One travels by train, steadily taking in the scenery; the other drives their own car, stopping at interesting places along the way. Both arrive at the destination of building wealth, with slightly different experiences. You decide which way of travelling feels right for you: do you prefer a carefree ride or the freedom to choose your own route?
ETF or index fund? In the end, the answer depends on what you value and what kind of investor you want to be. If you were looking for inspiration and insight, we hope this article provided it. Perhaps you noticed that investing really is not just cold numbers in Excel, but a personal way of building your future. Either route is better than standing still. The most important thing is to get started. You could, for example, start with an index fund and add a little ETF spice along the way, or the other way round.
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