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LearnMaster Your Money › Module 5 › Lesson 5.3

Rebalancing & Staying the Course Core

Rebalancing is the only mechanical process in investing that forces you to sell what has done well and buy what has done badly. It feels wrong every single time, which is roughly the point.

Module 5 · Lesson 5.3 3 lessons ~10 min Not started
The short answer

Portfolios drift because assets grow at different rates — left alone, a 70/30 portfolio becomes far riskier than intended. Rebalancing restores the target and is systematic buy-low/sell-high. Use calendar (annually) or threshold (when a holding drifts more than 5 percentage points) rules. Rebalance with new contributions first, which triggers no tax at all. Historically, investing a lump sum immediately beats dollar-cost averaging it in roughly two-thirds of the time — but DCA is easier to actually do.

By the end of this lesson you'll be able to

  • Explain why drift makes an unrebalanced portfolio riskier than intended.
  • Choose between calendar and threshold rebalancing and apply the 5% band rule.
  • Rebalance a taxable account without unnecessarily realising capital gains.
  • Write a one-page Investment Policy Statement that pre-decides your crash response.

Why portfolios drift, and why that is a problem

Set a portfolio to 70% stocks and 30% bonds and then do nothing. Stocks outperform for several years, and without a single decision on your part you now hold 82% stocks. You did not choose to increase your risk — the market chose for you, and it chose to increase it precisely after a long run-up, which is exactly when you would least want it increased.

That is drift, and it is relentless. Over a long bull market an unrebalanced 70/30 portfolio can end up 85/15 or higher. The investor believes they hold a balanced portfolio; they hold an aggressive one, and they find out during the next crash.

Worked example — five years of drift

A $100,000 portfolio starts at 70% stocks ($70,000) and 30% bonds ($30,000). Over five years stocks return 10% a year and bonds return 2%.

  • Stocks: $70,000 × 1.105 = $112,736
  • Bonds: $30,000 × 1.025 = $33,122
  • Total: $145,858 — of which stocks are now 77.3%
A 7-point increase in equity exposure, invisible unless you look. The portfolio is now meaningfully more volatile than the one you signed up for.

Rebalancing is simply selling enough of what grew and buying enough of what lagged to return to target. Mechanically, it forces you to trim the asset that has risen and add to the one that has fallen — systematic buy-low, sell-high, executed by a rule rather than by judgement. It will feel wrong every time, because you will always be selling the thing that is working.

One honest note: rebalancing is primarily a risk-control tool, not a return-enhancement tool. Over some periods it modestly improves returns; over long bull markets it modestly reduces them, because you keep trimming the winner. Its real job is keeping your portfolio at the risk level you chose.

Calendar or threshold?

Calendar rebalancingThreshold rebalancing
TriggerA fixed date — typically once a yearAny holding drifts more than 5 percentage points from target
AdvantageTrivially simple; no monitoringResponds to what markets actually did
DrawbackCan miss a large mid-year moveRequires checking, which invites tinkering

Both work. The evidence does not strongly favour either, and rebalancing more often than annually generally adds costs without adding benefit. What matters far more is having a rule and following it rather than deciding each time whether now feels like a good moment.

A sensible hybrid: check once a year on a fixed date, and rebalance if anything has drifted more than 5 percentage points. That is one calendar reminder and roughly ten minutes of work annually. If you hold a one-ticket asset-allocation ETF, this entire section is already handled inside the fund and you can skip it.

Rebalancing without triggering tax

In a TFSA or RRSP, rebalance freely — no tax event occurs. In a taxable account, selling an appreciated holding realises a capital gain and creates a tax bill, so the order of operations matters:

  1. Use new contributions first. Direct every new dollar into whatever is underweight. This rebalances gradually with zero tax consequence and no selling at all. For anyone still accumulating, this alone handles most drift.
  2. Use distributions. Rather than automatically reinvesting dividends back into the same holding, direct them to whatever is underweight.
  3. Rebalance inside registered accounts. If you hold the same asset classes across account types, do the selling inside the TFSA or RRSP and leave the taxable account alone.
  4. Sell in the taxable account last, and when you do, consider pairing it with realising a loss elsewhere to offset the gain (Lesson 6.1).
Why contribution-based rebalancing is underrated

It costs nothing, triggers no tax, requires no decisions, and happens automatically if you set your recurring purchase to whatever is currently underweight. For most people in the accumulation phase, new money does the entire job and explicit rebalancing is never needed. It is the clearest example in this course of a system that produces the right behaviour without asking you to be disciplined.

Equity weight drifting away from target and being rebalanced A line showing the equity share of a portfolio over ten years. It drifts above the seventy percent target during rising markets and falls below it during declines, with rebalancing events pulling it back to target each time. 70% 80% 60% target ten years → rebalance: trim stocks rebalance: buy stocks after the fall
The vertical drops are rebalancing events. Notice that each one sells after a rise and buys after a fall — the correct behaviour, enforced by a rule rather than by nerve.

Lump sum vs dollar-cost averaging

You receive $60,000 — an inheritance, a bonus, a house sale. Invest it all now, or spread it over twelve months?

The historical evidence is clear and slightly uncomfortable: investing the lump sum immediately has produced a better outcome roughly two-thirds of the time. The reason is simply that markets rise more often than they fall, so time out of the market usually costs more than the risk of a poorly timed entry.

And yet dollar-cost averaging is entirely defensible, for two honest reasons:

A reasonable compromise many people use: invest a meaningful portion immediately — half, say — and spread the rest over three to six months. It captures most of the expected advantage of being invested while capping the worst-case regret.

Note the important distinction: this debate is only about a lump sum you already have. Investing your paycheque monthly is not dollar-cost averaging in this sense — it is just investing money as it arrives, which is the only option available and is unambiguously correct.

The Investment Policy Statement

An Investment Policy Statement is one page, written while markets are calm, that answers in advance every question you will be asked by your own panic. Institutions have used them for decades; almost no individual investors do, which is odd given that individuals are far more likely to act emotionally.

A useful IPS covers six things:

  1. Goals and horizon. What this money is for and when you need it.
  2. Target allocation. The specific percentages, and the rebalancing rule and date.
  3. Contribution plan. How much, how often, into which account, automatically.
  4. What I will do when markets fall. Written explicitly: "If my portfolio falls 30%, I will continue my scheduled contributions and will not sell. I will review this statement, not my balance."
  5. What would legitimately change my mind. A genuine change in goals, horizon or circumstances — not a change in prices, headlines, or a forecast.
  6. How often I will look. A specific frequency, decided now.
Why writing it down works

During a crash you are not a rational analyst; you are a frightened person with a phone. An IPS means you do not have to decide anything in that state — you follow instructions written by someone who shared your goals, understood your plan, and was not afraid. That is a genuinely different psychological task, and it is the difference between a plan that survives contact with a bear market and one that does not.

The capstone at the end of this course generates a complete IPS from your own answers, which you can print and keep.

Common questions

How often should I rebalance my portfolio?

Once a year is plenty for most investors, either on a fixed date or whenever a holding has drifted more than about 5 percentage points from its target. Rebalancing more frequently adds trading costs and, in a taxable account, tax, without improving outcomes. If you hold a one-ticket asset-allocation ETF, the fund rebalances internally and you do not need to do anything at all.

Should I invest a lump sum all at once or spread it out?

Historically, investing a lump sum immediately has produced a better result about two-thirds of the time, because markets rise more often than they fall and time out of the market costs more than a badly timed entry. Dollar-cost averaging is still defensible: it caps the worst-case regret, and if spreading the entry is what gets the money invested at all, it wins by default. Investing half immediately and the rest over three to six months is a common compromise.

What is an Investment Policy Statement?

A one-page document, written while markets are calm, setting out what your money is for, your target allocation and rebalancing rule, your contribution plan, exactly what you will do if markets fall sharply, and what would legitimately cause you to change the plan. Its purpose is to move the decision-making out of the moment of panic. The capstone at the end of this course generates one from your own answers.

Key takeaways

  • Portfolios drift toward more risk during bull markets. Rebalancing restores the allocation you chose — it is a risk control, not a return booster.
  • Pick a rule — annually, or when a holding drifts 5 percentage points — and follow it rather than deciding each time.
  • Rebalance with new contributions and distributions first: no selling, no tax. In taxable accounts, sell last.
  • Lump sum beats dollar-cost averaging about two-thirds of the time, but DCA is easier to follow. A plan you execute beats one you abandon.
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Educational purposes only — not financial, investment or tax advice. RiskStock is not a registered dealer, adviser, or tax professional. Nothing in this course is a recommendation to buy or sell any security or product. Tax and benefit figures are for the 2026 tax year, were verified against official sources on 2026-07-27, and change annually — confirm your own numbers with the CRA and a qualified professional before acting.