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Trading Fees Explained: What Every Trade Really Costs You
The commission is only the visible part of the bill. A clear tour of spreads, custody and currency costs, and the simple arithmetic that shows why busy trading often costs more than it earns.
Trading fees are everything you pay to buy, hold and sell an investment: the broker's commission, the spread between the buying and selling price, custody charges and currency conversion. Each looks small on its own. Repeated across many trades, they can take a large slice of your return before the market has done anything at all. Here is how each one works, with numbers you can check.
In short
- A trade has a visible cost, the commission, and quieter ones: the spread, currency conversion and custody.
- Minimum charges hurt small orders most: a 5-euro minimum on a 500-euro order is 1% each way.
- Trading often multiplies every cost. At 0.5% per round trip, 48 round trips a year take about a fifth of an account.
- Under EU rules, investment firms must disclose costs and charges before and after you invest. Read them.
What are trading fees?
Think of a trade as a purchase with several invoices, only one of which arrives with your name on it. The commission is the obvious one. The others are built into prices, deducted quietly once a year or applied when your euros become dollars.
In Greece, people usually buy shares on the Athens Stock Exchange (ATHEX) through a local investment firm (known as an AEPEY), through a bank's brokerage service or through an online broker authorised elsewhere in the EU that offers its services in Greece. Firms based in Greece are supervised by the Hellenic Capital Market Commission; firms from other EU countries answer to their home regulator. Fee structures differ widely, so comparing them takes more than a glance at the headline commission.
Taxes are a separate matter. Rules on taxing sales, dividends and gains are set nationally and change over time, so check the current position with the Independent Authority for Public Revenue (AADE) or a tax adviser, not with a fee table.
The five costs behind every trade
Here is the full list, with illustrative numbers rather than any firm's actual prices.
| Cost | What it is | Illustrative example | How to keep it down |
|---|---|---|---|
| Commission | The broker's charge per order: flat, a percentage, or a percentage with a minimum | 0.10% with a 5-euro minimum: 5 euros on a 1,000-euro order | Fewer, larger orders; compare at your usual order size |
| Spread | The gap between the price you buy at (ask) and the price you sell at (bid) | Ask 10.02, bid 9.98: about 0.4% lost on an instant round trip | Liquid shares, limit orders, patience in thin markets |
| Custody | A charge for holding your securities | 0.2% a year on 20,000 euros: 40 euros | Check per-position and minimum charges |
| Currency conversion | A margin or fee when euros are changed into dollars or other currencies | 0.5% on 2,000 euros: 10 euros in, roughly 10 more on the way out | Fewer conversions; compare the rate, not only the fee |
| Fund ongoing charges | The yearly cost inside funds and ETFs, taken from the fund's value | 0.5% a year on 10,000 euros: 50 euros | Compare charges in the key information document |
The spread, a cost nobody invoices
If a share shows a buying price of 10.02 euros and a selling price of 9.98, buying 100 shares costs 1,002 euros and selling them straight back returns 998. You lose 4 euros and no fee appears on any statement. Large, heavily traded shares usually have narrow spreads. Smaller and thinly traded shares, on any exchange, can have spreads several times wider, which matters if you trade them often.
Worked examples: how frequent trading eats returns
The minimum-fee trap
You buy 500 euros of shares and pay a 5-euro minimum commission, so the position costs you 505. Selling costs another 5 euros. To get your 505 back, the shares must be worth 510 when you sell: a 2% rise just to break even. On a 5,000-euro order with the same 0.10% commission and 5-euro minimum, the break-even rise is only about 0.2%.
Two investors, one market
Two people each start with 10,000 euros. Say every round trip, a buy and a later sale, costs them 0.5% in commission and spread combined. The first makes two round trips a year: about 100 euros in costs. The second makes four a month, 48 a year, each time moving the whole account. Compounded, the costs take about 21.4% of the account, roughly 2,140 euros, in a year when the market goes nowhere.
To finish that year level, the second investor needs a gain of about 27% before costs, because recovering a 21.4% loss takes 27%. Few professionals manage that reliably. Brad Barber and Terrance Odean studied tens of thousands of household brokerage accounts in the United States and found that the most active traders trailed the market by a wide margin, with trading costs explaining much of the gap. Costs compound exactly like returns, only against you; the mechanics are the same as in how compound interest works.
What 0.05% per trade teaches in a game
Even a small commission adds up, and a game is a cheap place to feel it. In WallThrone every trade pays a 0.05% commission. Buy 10,000 play dollars of a WSX company and you pay 5 dollars; sell at the same price and you pay about 5 more. A round trip costs about 0.1%, so the price has to rise just over 0.1% before you are ahead.
That sounds trivial until you count. Prices on the WSX move every five seconds, and the urge to jump in and out never stops. Twenty round trips a day on a 10,000-dollar position cost about 200 dollars. Over five days that is 1,000 dollars, 4% of the 25,000 play dollars you start with, gone before a single trade goes wrong. Hired traders add a fixed cost of their own, an hourly salary: a fair reminder that people and platforms are expenses in any trading business.
Make the invisible bill visible. Play a week of WallThrone with a running tally of every commission you pay, then set it against your gains. Few exercises teach cost discipline faster, and only play money is at stake.
Track your costs in playHow to compare brokers' trading fees in Greece
- Confirm the firm is authorised: the Hellenic Capital Market Commission for Greek firms, the home regulator for firms from other EU countries.
- Get the full price list, not the advert: commissions per market (ATHEX, other European exchanges, the US), minimums, custody, currency, inactivity and transfer-out fees.
- Read the costs and charges disclosure that EU rules (MiFID II) require before you invest, and the key information document for any fund or packaged product.
- Model your real behaviour: your usual order size and how many trades you actually make in a year.
- Add everything up as a yearly percentage of the money you invest. That single number makes firms comparable.
- Once a year, compare the statement of costs actually charged with what you expected.
Fees are not the only criterion. Investor protection, a reliable platform and decent service matter too, and a cheap firm you do not trust is no bargain.
Are zero-commission brokers really free?
No firm works for nothing. When the commission is zero, the money usually comes from somewhere else:
- Wider spreads or currency margins, so the cost moves into the price you get.
- Interest on uninvested cash that the firm keeps rather than passes on.
- Securities lending of the shares you hold, where the terms allow it.
- Paid tiers for data, faster execution or extra features.
- Riskier products such as CFDs, where firms in the EU must show a warning with the share of retail accounts that lose money.
None of this makes a zero-commission broker a bad choice. It means the comparison has to include the whole bill. Cheap trading also has a behavioural cost: when a trade feels free, people tend to trade more, and overconfidence does the rest. The pattern is well described in the psychology biases behind overtrading.
Frequently asked questions
How much does it cost to buy shares on the Athens Stock Exchange?
It depends on the firm. Expect a commission, sometimes with a minimum per order, exchange and clearing charges that are often included in it, and possibly custody fees. Ask for the full price list and the costs disclosure, then price an order of your usual size. Any tax on transactions or gains is set by Greek law, so check it with AADE.
What is a reasonable commission for buying shares?
There is no single right number. What matters is your total yearly cost as a percentage of what you invest, including spreads, custody and currency conversion. A low headline commission with high currency charges can cost more than a higher commission without them. Compare firms at your real order size and trading frequency.
Do you pay fees when you sell shares as well as when you buy?
Usually yes. Most firms charge a commission on both sides of a trade, and you also cross the spread, buying at the higher price and selling at the lower one. That is why a round trip costs roughly twice the commission plus the spread. Some firms also charge to transfer your shares to another broker.
Is the spread a fee?
It is not invoiced, but it is a real cost. You buy at the ask and sell at the bid, and the gap is money you give up on every round trip. For large, liquid shares it is usually small; for thinly traded shares it can be several times larger. Limit orders let you control the price you accept.
This article is for education only and is not financial, tax or legal advice. WallThrone is a game played with play money on fictional companies; it is not a broker and gives no access to real markets.