ETF v praxi
How to Research an ETF Before You Buy: A Guide to the Key Sources
Key takeaways
- justETF lets you filter ETFs by asset class, TER, domicile, replication method, and fund size.
- The KID (Key Information Document) is a mandatory two-page document with a risk score, costs, and performance scenarios.
- The fund manager's factsheet contains holdings, Top 10 positions, geographic breakdown, and historical performance.
- Key parameters: TER, replication method (physical vs. synthetic), domicile, fund size, and spread.
- An Irish or Luxembourg domicile reduces withholding tax on US equity dividends from 30% to 15%.
Researching an ETF before buying means working through three sources: justETF for comparison, the KID for regulated information, and the factsheet for detailed holdings. None of them is sufficient on its own.
justETF: screener and filter
The website justETF.com aggregates data from across Europe and lets you filter by dozens of parameters. What you will find there:
- The annual fee TER and total cost of ownership TCO
- Fund domicile (Ireland, Luxembourg, …)
- Replication method (full physical, sampling, synthetic)
- Historical data and benchmark comparison
- Availability at specific brokers
Always filter for UCITS ETF — these comply with the European investor-protection regulation. Why domicile matters is explained in the article on Irish domicile.
KID: the mandatory two-page document
Every UCITS fund is legally required to publish a KID (Key Information Document). You can find it on the manager's website or through justETF. It contains:
- Risk indicator on a scale of 1–7
- Cost overview (entry, exit, ongoing)
- Recommended investment horizon
- Performance scenarios (stress, unfavourable, moderate, favourable)
Factsheet: detail from the fund manager
The factsheet is published directly by the manager (iShares, Vanguard, Amundi, …), typically monthly. You will learn the Top 10 largest holdings, sector breakdown, geographic weights, and how the fund deviates from its benchmark (tracking difference). Look for tracking difference — not tracking error. Tracking difference tells you by how much the fund lagged (or outpaced) the index for the year; tracking error tells you how much the deviation from day to day fluctuated.
Combine your research with what you are looking for: accumulating vs. distributing share classes are explained in the accumulating vs. distributing comparison. And broker selection in the Czech Republic, where you will actually buy the ETF, is covered in how to choose a broker.
FAQ
What is justETF and is it free?
justETF is a European ETF screener. The basic filters and fund overview are free. The premium version adds advanced backtests and portfolio construction tools. For standard ETF selection, the free version is more than sufficient.
What is the KID and where do I find it?
The KID (Key Information Document) is a mandatory regulated document issued for every UCITS fund. You can find it on the fund manager's website or through justETF in the documents tab. A valid KID must be available before purchase by law.
What is tracking difference and why does it matter?
Tracking difference (TD) is the difference between a fund's return and its benchmark over a given year. A negative TD means the fund outperformed the benchmark (for example through securities lending). TD is a more accurate indicator of real costs than the TER alone.
How do I know if an ETF is large enough?
The minimum fund size commonly cited is around EUR 100 million. Below that threshold the risk of higher spreads and fund closure increases. Large global ETFs typically have assets in the tens of billions of euros and are very liquid.