ETF v praxi
When to Switch from One ETF to Another — and When Not To
Key takeaways
- Switching ETFs is a sale and a new purchase — it triggers a taxable event.
- Legitimate reason: significantly lower TER, better tax domicile, or a different index composition.
- Poor reason: performance chasing or fear of a short-term drawdown.
- The time test resets after switching — watch out for holding periods.
- For large positions, calculate whether TER savings cover the tax cost of switching.
Switching from one ETF to another can make sense — but it is always a sale with tax consequences and a reset of the time test. That's why this decision is more complex than it looks.
What actually happens when you switch
Switching funds isn't a "transfer" — it's a sale of the existing ETF and a purchase of the new one. You realize a gain or a loss. If the time test isn't met, you pay tax on the gain. And the three-year test clock for the new fund starts from zero. If you're planning a switch, check the purchase dates of the old fund — selling just before the test is met is unnecessarily expensive.
When switching makes sense
- Significantly lower TER: If the new fund has a 0.15% lower annual fee, the saving compounds over ten years. Calculate whether the saving covers the tax cost and bid-ask spread of the switch.
- Better tax domicile: Irish-domiciled UCITS ETFs can be more advantageous for dividend taxation. More in why UCITS ETFs with Irish domicile.
- Different index: If you want to change your strategy (e.g. from S&P 500 to All-World), the switch is legitimate — but ask yourself honestly whether it's just performance chasing.
When not to switch
The most common mistake: investors switch from fund A to fund B because fund B "performed better last year." Past performance is no guarantee of future results. Similarly, a short-term drawdown is a poor reason — selling during a decline and buying a different fund is precisely what destroys long-term investor returns.
Regular investors: when to stop buying the old fund
If you've decided to switch but don't want to trigger a taxable event on your existing position, one option is simply to stop buying the old fund and direct new investments into the new one. The old position will naturally complete its time test. More on ETFs in the ETF section or in accumulating vs. distributing ETFs.
FAQ
Does the time test reset when switching to a different ETF?
Yes. Switching is a sale and a new purchase. The three-year time test for tax exemption starts from zero from the date of the new purchase. Selling just before the old test is met is tax-inefficient.
How do I know whether switching to a cheaper ETF is actually worthwhile?
Calculate the annual TER saving (difference in percentage × portfolio value) and compare it with the tax cost of switching (tax on unrealized gain) and transaction costs. For small positions, switching rarely pays off.
Is it better to stop buying the old fund or to sell everything and switch?
It depends on the situation. If you don't want to trigger a taxable event, stop buying the old fund and invest new money into the new one. The old position will naturally complete its time test.
Is it sensible to switch because of last year's better performance?
No. Performance chasing is one of the best-documented investor mistakes. Past fund performance does not predict future performance. Switch for structural and cost reasons, not results.