Rebalancing: Should You Really Sell What Is Working?

Imagine you created a portfolio with a deliberate allocation between equity and debt. Then equity performs strongly. Your portfolio grows — and the equity portion becomes much larger than you originally intended.

Now comes the uncomfortable question: should you sell some of what has worked well?

This is where rebalancing enters

Rebalancing means bringing a portfolio back toward its intended asset allocation after market movements or changes in circumstances have caused it to drift.

Why does a portfolio drift?

Asset classes do not move at the same speed. If equity rises much faster than debt, equity becomes a larger percentage of the portfolio even if you never bought another equity investment.

A simple example

Suppose your intended allocation is 70% equity and 30% debt. After a strong equity rally, the portfolio becomes 80% equity and 20% debt. Nothing was deliberately changed, but the risk profile has changed.

The hidden problem: your portfolio can become riskier without you noticing

The investor may feel successful because the portfolio has grown. But the same investor may now have more exposure to equity volatility than originally planned.

Rebalancing is not a prediction

This distinction matters. Rebalancing does not require you to believe that equity will fall or debt will outperform next. It is primarily about restoring a chosen portfolio structure.

Why does rebalancing feel psychologically difficult?

Because it can require selling an investment that has performed well and adding to one that has not. Human behaviour naturally prefers to hold winners and avoid recent disappointments.

But the portfolio is the unit that matters

The objective isn't to identify the next winning asset class. It is to maintain an allocation that remains appropriate for the goal and risk capacity.

How often should you rebalance?

There is no single universal schedule. Some investors use a calendar approach, such as reviewing annually. Others use a threshold approach, reviewing when an allocation moves materially away from its target. The right method should be practical and consistent.

Calendar-based rebalancing

A calendar approach creates a routine. For example, you might review the portfolio at a defined interval regardless of market headlines. The advantage is simplicity.

Threshold-based rebalancing

A threshold approach focuses on the size of the drift. For example, a portfolio might be reviewed when an asset class moves sufficiently away from its intended allocation. The exact threshold should be appropriate to the portfolio and circumstances.

You don't always need to sell

Rebalancing can sometimes be achieved by directing new contributions toward the underweight asset rather than selling existing holdings. This can reduce unnecessary transactions, depending on the portfolio and applicable costs or taxes.

What about withdrawals?

Planned withdrawals can also affect allocation. Money being withdrawn from an overweight asset can sometimes move the portfolio closer to its target without a separate sale purely for rebalancing.

Rebalancing can be behavioural discipline

Without a framework, investors may repeatedly add to what has recently performed well. A rebalancing rule creates a reason to do something different: restore the intended structure.

Does rebalancing improve returns?

Not necessarily. Rebalancing is primarily a risk-management and portfolio-discipline process. It can sometimes improve outcomes and sometimes reduce exposure to an asset that continues to outperform. The purpose should not be to promise superior returns.

What if the market keeps rising after you rebalance?

That can happen. Rebalancing may reduce exposure to an asset before it rises further. That does not automatically mean the decision was wrong if the original allocation was appropriate.

What if the market falls after you rebalance?

That can happen too. Rebalancing is not a guarantee against losses. Its purpose is to maintain the portfolio structure, not predict the next market move.

When should you NOT blindly rebalance?

A portfolio should not be treated as a machine that ignores real life. A major change in goals, timeline, income, liabilities or risk capacity may justify changing the target allocation itself rather than simply restoring the old one.

The target allocation can change

If you are five years from a goal instead of fifteen, the appropriate portfolio may be different. If your financial capacity changes materially, the risk you can take may change too.

Rebalancing versus changing strategy

Rebalancing asks: 'Have I drifted away from the allocation I still want?' Changing strategy asks: 'Is the allocation itself still appropriate?' These are different questions.

Taxes and transaction costs matter

Selling investments can create taxes or transaction costs depending on the product, holding period and applicable rules. Rebalancing should therefore consider implementation costs rather than treating every drift as a reason to trade.

Don't rebalance every time the market moves

Markets move continuously. If every small movement triggers an allocation change, rebalancing becomes market noise. A defined framework can prevent unnecessary activity.

A useful rebalancing checklist

Ask: What is my target allocation? How far has the portfolio drifted? Has my goal changed? Has my risk capacity changed? Can new contributions correct some of the drift? What are the tax and transaction

implications? Is there a genuine reason to change the target rather than restore it?

The 'why did I choose this allocation?' test

Before rebalancing, revisit the original reason for the allocation. If the reason remains valid, restoring the structure may make sense. If the reason has changed, the portfolio may need a broader review.

What this does NOT mean

Rebalancing does not mean selling every winner, buying every loser, timing the market, guaranteeing higher returns or following a rigid schedule regardless of circumstances.

A better rebalancing framework

TARGET → CURRENT ALLOCATION → DRIFT → LIFE CHANGES → IMPLEMENTATION COST → ACTION. Start with the intended portfolio, measure the drift, check whether your circumstances changed and then choose the least disruptive way to restore an appropriate structure.

North Horizon perspective

We view rebalancing as a portfolio-maintenance discipline, not a prediction exercise. A good allocation should be reviewed when circumstances change and maintained when market movements cause unnecessary drift.

A simple framework to remember

MARKET MOVES → PORTFOLIO DRIFTS → REVIEW → REBALANCE IF APPROPRIATE

The North Horizon takeaway

Selling something that has worked well can feel wrong. But the question is not whether the investment is a winner. The question is whether the portfolio still carries the amount of risk you intended to take.