Strategie
When to Change Your Investment Strategy — and When to Stubbornly Stick to It
Key takeaways
- Switching strategy after a downturn is one of the most common and costly mistakes — you sell cheap and buy high.
- A good reason to change is a change in life circumstances, not a market move.
- Strategy changes should be based on facts, not feelings — ask whether the underlying assumptions have changed.
- Short historical underperformance is too weak a reason to change strategy — markets have cycles.
- An investment journal and a written thesis help you distinguish a rational revision from panic.
Deciding when to change a strategy and when to stay the course is one of the hardest skills in investing — and it is precisely at this point that most investors lose their returns.
Why switching strategies is expensive
An investor who moves from global ETFs to bonds after three years of decline locks in the loss and misses the recovery. Historically, major downturns (2000–2002, 2008–2009, 2020) each ended in recovery — but only for those who held on. Data shows that retail investors earn on average less than the funds they invest in — precisely because of poorly timed shifts.
Bad reasons to change strategy
- The portfolio is down 20–30% and it makes you feel sick.
- You read an article or heard a tip that "now is the time for a different approach."
- The strategy bores you and you want some action.
- Another investor tells you your approach is outdated.
Good reasons to change strategy
- Your life circumstances changed — horizon, income, expenses, risk profile.
- The original assumptions of the thesis turned out to be factually wrong (not just temporarily unfavourable).
- The original strategy was never written down and it is time to fix that.
- The portfolio has drifted significantly from the target allocation and it is time to rebalance.
How to set the rules in advance
The best time to write rules for changing strategy is when you are calm — not in the middle of a downturn. Put a sentence in your investment journal: "I will change this strategy if..." and define specific conditions. Then stick to them. Just as the investment thesis protects against impulsive purchases, pre-defined rules protect against impulsively changing the entire strategy.
FAQ
When is the right time to change an investment strategy?
When your life circumstances change (horizon, income, obligations), or when the original thesis assumptions turn out to be factually wrong. A temporary market decline or bad mood are not sufficient reasons.
How do I stop a panicked decision in advance?
Write down — calmly, before the first purchase — the conditions under which you will change the strategy. Then stick to them. In a downturn, refer back to them and verify whether those conditions have actually occurred, or whether you are simply experiencing emotions from the decline.
What is the most expensive mistake when switching strategies?
Selling after a downturn and buying a different asset that has meanwhile risen. You lock in the loss and shift to the heights. Historical data shows that retail investors systematically lag the returns of the funds they invest in by doing exactly this.