Rebalancing and the annual review

You built a simple portfolio with a deliberate shape — say a chosen split between growth and stability. Leave it alone for a few years and a curious thing happens: the shape changes on its own, without you touching anything. The slices that rose fastest swell to a bigger share of the whole, the slices that lagged shrink, and the careful allocation you set drifts away from what you decided. This chapter is about the light, disciplined maintenance — rebalancing and an annual review — that pulls it gently back, and just as importantly, about resisting the urge to do more than that.

The skill here is almost paradoxical: doing a small, specific amount of maintenance on a schedule, while doing nothing the rest of the time. Most portfolio damage comes not from neglect but from over-management — anxious tinkering, chasing performance, reacting to every headline. The right maintenance is rare, rule-based, and calm. We're learning to touch the portfolio less, but deliberately.

Why a portfolio drifts

Drift is just arithmetic. If your equity slice grows much faster than your stability slice over a strong few years, equity becomes a larger fraction of the total than you intended — your portfolio has quietly become more aggressive than the risk profile you chose, purely because the winners grew. The reverse happens after a crash: equity shrinks, stability becomes a bigger share, and the portfolio drifts more conservative than you wanted, often right when equity is cheapest.

This matters because the allocation was set to match your risk profile and goals. Left to drift, the portfolio slowly stops reflecting you and starts reflecting whatever the market did lately — typically becoming riskiest after a long bull run (just when caution is wise) and most timid after a crash (just when boldness pays). Drift, unchecked, nudges you toward exactly the wrong posture at exactly the wrong time.

What rebalancing actually does

Rebalancing is the act of restoring your portfolio to its target allocation — trimming the slices that have grown too large and topping up the ones that have shrunk, until the shape matches your plan again. It sounds modest, and it is, but it does something quietly profound: it enforces a disciplined, contrarian behaviour automatically, without requiring you to be brave.

Look at what rebalancing forces you to do. When equity has run up and become overweight, rebalancing makes you sell some of the thing that rose and buy more of the laggard — you trim the expensive and add the cheap. After a crash, when equity is underweight and frightening, rebalancing makes you buy more of the thing that fell. It mechanically nudges you toward 'sell high, buy low' at the precise moments your emotions are screaming the opposite. You don't have to feel brave; you just follow the rule.

How and when to rebalance

Rebalancing should be rule-based and infrequent, never a constant fiddling. There are two clean triggers, and you pick one and stick to it rather than rebalancing on a whim or a mood.

• Time-based — check on a fixed schedule, most commonly once a year, and rebalance back to target if things have drifted. Simple, calm, and easy to stick to.
• Threshold-based — rebalance only when a slice has drifted beyond a set band (for instance, more than a chosen number of percentage points off target), regardless of the date.
• A blend — check on a schedule, but only actually trade if the drift is large enough to be worth the bother and any costs. This is often the most practical for ordinary investors.

The annual review: a wider, calmer look

Once a year — pick a fixed date and keep it, so it's a ritual, not a reaction — do a broader annual review that steps back from the holdings to look at the whole picture. Rebalancing asks 'has the portfolio drifted from its target?' The annual review asks the bigger question: 'is the target itself still right for the life I'm now living?'

1. 1Has my life changed? A new dependant, a job change, a major expense, a goal that's drawn much nearer — any of these can shift your risk capacity and may mean the target allocation itself should change.
2. 2Are my goals still on track? Check whether each goal's funding is roughly where it should be; adjust the SIP amounts if a goal is lagging or if your income has grown and you can do more.
3. 3Has my risk profile shifted? Revisit the honest risk question, especially if you've now lived through a downturn — experience often genuinely changes tolerance.
4. 4Do the foundations still hold? Is the emergency fund still adequate for current expenses, the insurance still sufficient, any new costly debt dealt with?
5. 5Then, and only then, rebalance back to the (possibly updated) target.

The discipline of leaving it alone

Step back and see what this maintenance routine really is: a defence against yourself. The market will constantly tempt you to act — to chase the winner, flee the loser, react to the headline, do something. A fixed-schedule rebalance and a calm annual review give you a structured, rare, rule-based outlet for that urge, which protects you from the far more expensive habit of acting on impulse all year long. You channel the itch to manage into two disciplined moments and stay still the rest of the time.

That stillness is not laziness — it's the active discipline that lets compounding run uninterrupted, keeps costs and taxes low, and stops emotion from steering. The investor who rebalances calmly once a year, reviews their goals annually, and otherwise leaves a simple portfolio alone will, over decades, very likely beat the one who watches daily and tinkers constantly. You've now built the whole chain — fund, goals, risk, tax, portfolio, maintenance. The rarest and most valuable skill left is simply the patience to let it work.