Rebalancing Your Portfolio at Record Highs (2026)

If your portfolio is sitting at an all-time high right now, it is probably also further from your target allocation than it has been in months. That is not a coincidence. When markets run, your winners grow faster than everything else, and the mix you carefully chose quietly tilts toward whatever just rallied hardest. Learning how to rebalance your portfolio is how you take that risk back off the table without trying to time the market.

The timing is not hypothetical. In the first week of July 2026, Europe's STOXX 600 hit an intraday record and Germany's DAX notched an all-time high, its biggest weekly jump in over a month, led by cyclicals and chip names like Aixtron and Soitec (Reuters via US News). If you hold European equities, your allocation moved this week whether you traded or not.

This guide covers what rebalancing actually does, why record highs create the most drift, the methods worth using, and how to do it in Europe without walking into an avoidable tax bill.

What Rebalancing Actually Means

Rebalancing is the act of returning your portfolio to its target weights by trimming positions that have grown too large and topping up ones that have shrunk. If you decided on 60% stocks and 40% bonds, and a rally pushed you to 70/30, rebalancing sells enough stock (or buys enough bonds) to get back to 60/40.

That is the whole idea. It is not a prediction about where the market goes next. It is a rule that forces you to sell a little of what is expensive and buy a little of what is cheap, on autopilot, at a moment when your emotions are pulling you the opposite way.

The discipline matters most precisely when it feels least necessary. At record highs, trimming your best performer feels like a mistake. That reluctance is the exact reason a rule beats a gut call.

Why Record Highs Create the Most Drift

Asset allocation drift is the gap between the weights you chose and the weights you actually hold. Prices move, and the gap widens on its own.

Consider a simple case. You start the year with €10,000 split evenly across five holdings, €2,000 each, 20% weights. One of them, say a semiconductor stock, doubles during a chip rally while the others stay flat. Now that single position is worth €4,000 out of €14,000 total. It is 29% of your portfolio, not 20%, and you never placed a trade to make it so.

Scale that up to a broad rally like July 2026, where an entire index prints records, and the effect compounds. Your equity sleeve swells against your bonds and cash. Within equities, whatever sector led (this time, cyclicals and chips) balloons against the laggards. You end up more concentrated, in the frothiest corner of the market, right as valuations stretch.

That is the trap. Concentration risk arrives quietly, disguised as good news. A portfolio that looks like it is winning can be carrying far more risk than its owner ever intended.

The ECB's surprise 25bp hike in June 2026, which lifted the deposit rate to 2.25% as eurozone inflation hit 3.2%, adds another reason to check your mix. Rate moves reprice sectors unevenly, so the same rally that inflated your winners may also be shifting the risk profile underneath them.

When to Rebalance: Calendar vs Threshold

There are two sane ways to decide when to rebalance, and you can combine them.

Calendar rebalancing means you check on a fixed schedule, usually once or twice a year, and reset to target regardless of what markets have done. It is simple, it is easy to stick to, and it stops you from fiddling. The downside is that a big move between check-ins goes unaddressed until the date rolls around.

Threshold rebalancing means you act only when a holding drifts beyond a set band, say 5 percentage points from its target, or 25% of its own weight (a 20% position becoming 25% or 15%). This is often called the 5/25 rule. It ignores small wiggles and responds to the moves that actually matter, like a record-high melt-up.

For most self-directed European investors, a hybrid works best: check on a calendar (twice a year is plenty), but also act if any position breaches your threshold in between. That combination catches a week like this one without turning you into a day trader. Rebalancing more than a handful of times a year tends to pile on costs and tax without improving returns.

If you have never set target weights in the first place, start with our guide to portfolio diversification before worrying about drift. You cannot measure drift against a target you never defined.

How to Rebalance Without a Tax Bill in Europe

This is where European investors need to be careful, because the naive method (sell your winners, buy your losers) can hand you an avoidable tax bill.

The tax treatment of selling depends entirely on where you live:

Because of this, the most tax-efficient way to rebalance is to rebalance with new money first. Instead of selling your overweight winner, direct your next few monthly contributions and any incoming dividends toward the underweight positions until the mix comes back into line. No sale, no realized gain, no tax event in most countries. Reinvested dividends are quietly one of the best rebalancing tools you have, because the cash arrives anyway and you simply point it where it is needed.

Only when new contributions cannot close the gap fast enough (for example, one position has become wildly oversized) does selling become worth the tax cost. Even then, if you are in Germany, France, or now Belgium, size the sale against your annual exemption and consider spreading it across two tax years.

Dutch investors have more room here, since Box 3 taxes assumed returns on wealth rather than the act of selling, so trimming a winner does not itself create a capital gains bill. Anyone unsure should confirm the specifics with a tax advisor for their country, because these rules change and 2026 has already brought new ones.

You Cannot Rebalance Drift You Cannot See

Here is the practical problem. To rebalance, you need to know your real current weights, across every holding, in one currency. Degiro's own interface will show you positions and a portfolio value, but it will not lay out your allocation by sector, by country, and by asset class in a way that makes drift obvious at a glance. Neither will a spreadsheet you last updated in April.

This is the gap a portfolio tracker fills. Zune.Money imports your Degiro transactions from a single CSV and shows your allocation broken down by asset class, sector, and country, with each holding's real weight in your base currency. The position that quietly grew to 29% stops being a surprise, because you can see it. If you are still tracking by hand, our walkthrough on getting started with portfolio tracking shows how to set this up in a few minutes.

Seeing your true country and sector split also surfaces a subtler drift. If US tech has carried your returns for two years, you may be far more concentrated in one region than you realize, a point worth weighing against the case for rotating some European exposure back in. Allocation you cannot see is allocation you cannot manage.

A Simple Rebalancing Checklist

Here is the process, start to finish:

1. Write down your target weights. By asset class first (stocks, bonds, cash), then optionally by region or sector. If you have never done this, that is step zero.
2. Pull your real current weights. Import your transactions into a tracker so you see actual allocation, not guesses. Note anything that has drifted past your threshold.
3. Rank the gaps. Which positions are most overweight, and which are most underweight? Focus on the breaches, not every 1% wobble.
4. Route new money first. Point upcoming contributions and reinvested dividends at the underweight positions before you consider selling anything.
5. Sell only if you must, and mind the tax. If new money cannot close the gap, trim the overweight winner, sized against your country's capital gains exemption.
6. Write down the date and set the next check. Twice a year is a sensible default, plus any threshold breach in between.

Want to see how disciplined rebalancing changes an outcome over time? Our portfolio growth simulator lets you model contributions and compounding, so you can pressure-test a plan before you commit real euros to it.

The Takeaway

Record highs are a gift and a warning at the same time. Your portfolio is worth more, and it is almost certainly riskier than you intended, because the winners have quietly taken over. Rebalancing is the unglamorous habit that turns a lucky rally into a portfolio you actually chose. Do it on a schedule, respond when a position drifts too far, use new money before you sell, and above all, make sure you can see your real allocation before you touch anything. The market hitting a new high is not the moment to look away.

This article is general information for European investors, not financial or tax advice. Tax rules vary by country and change often, so confirm your own situation with a qualified advisor.