Estimate how a small annual fee compounds against you over decades.
Spot where a broker's real costs are hidden.
Almost every broker you'll meet advertises "commission-free" or "0€ per trade." None of them are charities. The money still gets made, it just moves to places you don't see on the order screen. This lesson maps where it goes. Once you can spot the hidden costs, you can pick a broker whose pricing actually fits how you behave, instead of one whose marketing fits how you feel.
There's nothing sinister here. A business charging for its service is normal. The problem is only when the charge is invisible to you, because then you can't compare brokers properly and you can't tell whether your own habits are quietly expensive. So the goal is plain literacy: name each cost, know roughly what it runs in the EU, and know which of your behaviours trigger it.
The six places "free" gets paid for
Cost #1 · every trade
The spread (bid/ask)
At any moment there's a price you can buy at (ask) and a slightly lower price you can sell at (bid). The gap is the spread, and the broker or market-maker keeps it. On a liquid stock it's tiny; on a thin or volatile asset it widens. You pay it twice — once going in, once going out — and you pay it whether the trade wins or loses. This is the quiet workhorse of "commission-free."
Cost #2 · holding overnight
Swap / overnight financing
If you hold a leveraged or CFD positionovernight, you're effectively borrowing money, and you pay daily interest on it — the swap. It can run for or against you, but for most retail it's a steady drip out. A position that looked flat all month can still lose money purely to swap. Plain (unleveraged) stock you own outright generally has no swap.
Cost #3 · behind the order
Payment for order flow
Some brokers route your order to a market-maker who pays the broker for the privilege of filling it — PFOF. You don't see a fee, but you may get a marginally worse fill than you could have. Relevant for EU investors: PFOF is banned in the EU(a transitional exception in some member states — notably Germany — runs only until 30 June 2026), so it's disappearing as a revenue source here. Brokers that leaned on it have to replace that revenue somewhere — usually in the spread.
Cost #4 · the EU classic
Currency-conversion (FX) fee
You hold euros. You buy a US stock priced in dollars. Somewhere your EUR gets converted to USD, and the broker takes a slice on the conversion — often 0.5% to 1.5%, sometimes baked into the rate so you never see it itemised. For a European buying US assets this is frequently the single biggest hidden cost, and it hits both on the way in and the way out.
Cost #5 · getting money in/out
Withdrawal & inactivity fees
Many brokers charge a flat fee to withdraw cash (e.g. a fixed few euros per withdrawal), and some charge inactivity feesif you don't log in or trade for a stretch of months. Neither shows up when you're buying. They show up later, which is exactly why people forget to price them in when choosing a broker.
Cost #6 · social & crypto
Copy / social fees & crypto markup
Social features (copying another investor, copy portfolios) can carry their own fees or spread their cost through wider spreads. Cryptois usually monetised through a markup baked into the buy/sell price rather than a stated commission. Both are easy to overlook because the number on screen looks like "the price," not "the price plus a margin."
The one idea to keep
"Free" never means free. It means the cost moved somewhere less visible — usually into the spread, the FX conversion, or overnight financing. Your job isn't to find a broker with zero costs (there isn't one). It's to find one whose costs land on things you don't do much, and avoid one whose costs land squarely on your actual habits.
Why the FX fee matters so much in Europe
If you're investing from the eurozone and you want exposure to US tech, US indices, or most large global names, you're buying dollar-denominated assets. Every euro you put in gets converted, and every euro you take out gets converted back. A conversion fee of around 1% doesn't sound like much until you notice it applies to the whole amount, every round trip, regardless of whether the trade made money.
Compare that to a stock spread, which on a liquid name might be a few hundredths of a percent. For a buy-and-hold European investor in US assets, FX conversion can quietly outweigh every other cost combined. This is why "is the trade commission-free?" is the wrong first question. "What does it cost me to convert my euros, and how often will I do that?" is closer to the real one.
How to actually read a broker's costs
You don't need a spreadsheet. You need to match each cost to your own behaviour, in this order:
1
Write down what you'll actually do
Buy-and-hold or frequent trading? Euro assets or US/foreign ones? Leverage/CFDs or plain ownership? Crypto or not? Will you withdraw often? Your honest answers decide which costs even apply to you.
2
Find the FX conversion rate
If you'll buy foreign-currency assets, this is usually your biggest lever. Look for the conversion fee (often stated as a percentage, sometimes hidden in the exchange rate they use).
3
Check spreads on what you'll trade
Look up the typical spread for the specific assets you care about, not a cherry-picked example. Thin or exotic instruments have wider spreads, and you pay it on entry and exit.
4
Read the overnight/swap terms — only if you use leverage
If you'll never hold leveraged or CFD positions, you can skip this. If you might, find the daily financing rate, because it compounds quietly over time.
5
Find the boring fees
Withdrawal fee, inactivity fee, any account or conversion minimums. They're usually in a fee schedule, not the marketing page. These decide the long-run cost more than the headline does.
eToro, factually
As one concrete example: eToro tends to monetise through the spread on instruments, a currency-conversion fee when your deposit currency differs from the account/asset currency, a flat withdrawal fee, an inactivity fee after a long dormant period, and a spread/markup on cryptorather than a stated commission. This is neither good nor bad on its own — it's just where the money is. Whether it suits you depends entirely on your behaviour: a euro-based, frequent-withdrawing investor feels the FX and withdrawal costs more than a dollar-funded, rarely-withdrawing one. Always check the current published fee schedule, since numbers change.
Try first
Two brokers. Broker A charges a small explicit commission per trade but has a 0.15% FX fee. Broker B is "commission-free" with a 1.5% FX fee. You're a euro investor buying US shares a few times a year and holding. Which is likely cheaper, and why?
Don't let the headline pick for you
"Commission-free" is a marketing phrase, not a measure of total cost. A broker can be commission-free and still be the most expensive option for you because of FX, spread, or withdrawal fees. Judge brokers on the costs your behaviour actually triggers, not on the largest font on the homepage.
See what a fee really costs
A fee looks trivial as a percentage. Drag it and the years out — it compounds against you exactly the way returns compound for you. This is why "free" brokers, and where their costs hide, actually matter.
InteractiveFee drag — what a 'small' fee really costs
no fee after 1.0%/yr
Without the fee
€365.991
With the fee
€301.355
Lost to fees
€64.637
Hypothetical projection at a constant rate — illustrates the cost of fees, not a forecast of returns.
A fee compounds against you the same way returns compound for you. 1.0%/year sounds tiny, but over 30 years it quietly removes €64.637 here. This is the real reason the brokers lesson matters. Illustrative math at a constant rate — not a forecast or advice.
Check yourself
Check yourself
1.A broker advertises "0% commission." What does that reliably tell you about your total cost?
2.You're a euro-based investor buying and holding US stocks, adding money monthly. Which cost is most likely to dominate?
3.What is the swap (overnight financing) fee, and who pays it?
4.Why is payment for order flow (PFOF) going away as a revenue source for EU brokers?