Nástroje, automatizace a praxe
Automated Rebalancing: How to Set It Up and When It Pays Off
Key takeaways
- Threshold rebalancing (when drift exceeds 5–10%) is more efficient than calendar rebalancing (every month).
- The simplest automation: direct new contributions to the underweighted asset class.
- Selling and buying for rebalancing purposes generates taxable events — prefer reinvesting contributions.
- Most robo-advisers rebalance automatically but charge a fee for it.
- Never rebalance just because the market fell — the drift must exceed your threshold.
Automated rebalancing is a system of rules that keeps your portfolio close to the target allocation without requiring active decision-making on every purchase.
Calendar vs. threshold rebalancing
There are two basic approaches. Calendar rebalancing is done on a fixed schedule — once a year or quarterly — simple, predictable, but it ignores the actual drift. Threshold rebalancing acts only when an asset class drifts from the target by more than a defined threshold — typically 5 or 10 percentage points. The threshold approach is generally more efficient and generates fewer tax events.
The simplest form of automation: redirecting contributions
Before every monthly purchase, check the current allocation in your tracker. Invest the entire new contribution in the underweighted asset. This pulls the portfolio back towards the target without any sales — no tax costs, no selling fees. It works well as long as regular contributions are large enough relative to the total portfolio value.
When to sell and buy (hard rebalancing)
If contributions are small or the drift exceeds 10 p.p., it is time to sell the overweighted asset and buy the underweighted one. Consider the tax impact — sales after 3 years are generally tax-exempt (see the tax calendar). Selling before three years means the gain enters the tax base.
Robo-advisers and platform-level automation
Some platforms (Fondee, Portu) rebalance automatically. This is convenient but comes at a cost. For DIY investors, a combination of a tracker and the contribution-redirection rule is enough — you can manage it yourself in 5 minutes per month.
FAQ
How often should I rebalance my portfolio?
For most passive investors, rebalancing once a year or when a threshold drift of 5–10 percentage points is exceeded is enough. More frequent rebalancing generates unnecessary fees and tax events with no demonstrable return benefit.
How do I rebalance without incurring tax costs?
The most efficient way: redirect new contributions to the underweighted asset. This brings the portfolio back into balance without any sales — no taxable events. It works as long as regular contributions are reasonably large relative to the total portfolio value.
Does it make sense to use a robo-adviser just for automatic rebalancing?
For many investors, no. Redirecting contributions to the underweighted asset class takes 5 minutes per month on your own. A robo-adviser fee of 0.5–1% per year is a significant amount over 20 years. A robo-adviser makes sense if you appreciate the overall management and have no desire to engage with your portfolio at all.