Should you rebalance, and how?

When I first started investing, I had a misconception: I thought “holding long term” meant “buy it and do nothing.” Later I realized doing nothing has a hidden danger — as something rises and rises, its share of your total portfolio quietly grows, and so does the risk, without you noticing. Rebalancing is a very plain action used to deal with exactly that.

What rebalancing is

Put plainly, rebalancing is periodically adjusting the ratios of your asset classes back to the target you originally set.

An example. Suppose your set allocation is: crypto at 10% of total assets, the other 90% in savings, funds, and the like. A year passes, crypto soars, and now it's 20%. The rebalancing move is to sell some crypto, bring its share back to 10%, and put the proceeds into your other assets. The reverse too: if crypto fell to just 5%, you'd consider topping a bit back up, bringing it to 10%.

The key is that rebalancing watches the “ratio,” not “whether I think it'll rise or fall.” You don't need to forecast the market, only glance at how far the current share has drifted from target, then adjust it back. How this rule combines with the “core + satellite” allocation I break down in more detail in core and satellite: how to arrange your money.

Trim after a big rise, top up after a big fall: why go against the grain

Many beginners' first reaction is: it's rising nicely, why sell? It's fallen this hard, why dare to top up? Isn't this against human nature?

It is a bit against human nature, but the logic behind it is solid:

Trim after a big rise because the risk has quietly exceeded your limit. Crypto going from 10% to 20% means a fifth of your total assets is now riding on the most volatile thing you own, which is already beyond the risk you were originally willing to bear. Trimming a little here isn't picking a fight with your money, it's actively dragging the risk back to a level you can sleep on. As a bonus, you've also genuinely banked some of the paper gain, rather than watching it climb and then fall back.

Top up after a big fall can make sense because the current share is below what you consider reasonable. But add a precondition — the money for topping up must be spare money beyond your emergency fund, and don't top up with no cap (this is precisely one of the mistakes beginners make most). While holding to your overall cap, topping back up when it falls below target essentially means buying more of the cheap share while it's cheap.

How often a beginner should check

This is the point I most want to stress: don't touch it every day. The mistake beginners make most isn't “forgetting to rebalance,” it's “adjusting too often.”

My own approach, which is also the two fairly common lines of thinking:

• By time: a fixed check every six months or year. When the time comes, open the account, work out the current ratio, adjust if it's drifted from target, leave it if it hasn't drifted much. The rest of the time, you needn't even look.
• By threshold: set a drift line, say “only act when crypto's share strays more than 5 percentage points from target.” If the target is 10%, you only move when it rises past 15% or falls below 5%, and ignore all the swings in between.

Why stress not too often? Three concrete reasons: every move has a fee, and frequent action adds up; selling may involve tax, depending on where you live; and most fatally, the more often you act, the more easily you're led by the nose by short-term swings, turning a rule that should be executed mechanically into chasing rallies and dumping on dips. Checking once or twice a year actually lets you keep a calm mind.

Rebalancing vs chasing rallies and dumping on dips

On the surface both of these can be “selling” or “buying,” but their cores are completely opposite — never confuse them.

	Rebalancing	Chasing rallies, dumping on dips
Basis	Current ratio has drifted from target	Emotional reaction to short-term moves
Direction	Trim after a rise, top up after a fall (against the grain)	Chase when up, cut when down (with emotion)
Frequency	Once every six months to a year, by rule	Itchy hands anytime, watching news and group chats
Goal	Keep risk in a fixed band	Catch every wave, fear of missing out

See it now: rebalancing is cold, chasing and dumping is hot. Rebalancing has you “trim when up, top up when down” because the ratio rule requires it, regardless of your present fear or greed; chasing and dumping is the opposite — emotion placing the order for you. To judge which one you're actually doing, there's a simple test: is this action one that a rule I set six months ago tells me to do, or one I came up with on a whim after looking at the market today? The former is rebalancing; the latter is most likely chasing and dumping.

Recap: it's a rule, not a forecast

To wrap this in one line: rebalancing is a rule for periodically adjusting the ratio back to target — not a forecast of ups and downs. Set the target ratio and frequency, and when the time comes, execute mechanically — trim after a rise, top up after a fall, don't look in between. It helps you do something a beginner struggles to do on willpower alone: bring yourself to trim when you should, dare to top up when you should, and not fiddle blindly every day.

But rebalancing has a precondition: you first need a clear “target ratio.” How much crypto should be of your total assets, and how to set that number, is exactly what the next piece gets into.