Rebalancing sounds boring until one part of your portfolio has run so far that it starts making decisions for you. A strong market can be wonderful. It can also leave you more concentrated than you intended. You are not punishing winners; you are keeping risk close to what you meant to take.
Risk match, not a calendar superstition
“Rebalance every year” or “at 5% drift” is a starting rule, not a law. The useful benefit is keeping risk close to the plan — trimming winners and topping up laggards when drift is large enough to matter — not hitting an exact anniversary. Skipping rebalancing entirely because it feels like “selling winners” lets risk wander. Over-trading for tiny drifts can create taxes and costs. Ask: does the portfolio still match the risk you meant to take? If yes, leave it. If no, adjust with a plan.
This page covers allocation drift after a run. For whether a market drop should change behavior at all, start with What Should a Market Pullback Actually Change?
What changed from your target?
Can contributions fix it gradually?
Where does selling create a cost?
What rebalancing really means
Imagine your target is 80% stocks and 20% bonds or cash-like stability. After a strong stock run, you may be at 88% stocks and 12% stability without buying anything new. Your plan became more aggressive because prices moved.
Rebalancing means bringing the portfolio closer to the target. You can do that by selling some winners, buying more of what lagged, directing new contributions, or a mix of all three.
Bands beat constant tinkering
Checking every tiny movement creates noise. Set bands instead. If your stock target is 80%, you might rebalance only when it drifts below 75% or above 85%. That gives prices room to move while still catching risk that has wandered too far.
Bands also make decisions less emotional. You are not selling because a headline scared you. You are acting because the portfolio crossed a rule you set ahead of time.
New contributions first
If you are still adding money, you may not need to sell anything. Send new contributions toward the underweight area. If stocks have run, new money can go to bonds, cash, international funds, value funds, or whatever part of your plan is below target.
In taxable accounts, that often avoids triggering gains. Psychologically it helps too: you are not abandoning winners; you are feeding the parts of the plan that need attention.
A household example
Sam and Riley target 75% growth assets and 25% stabilizers. After a strong run, growth assets drift to 84%. That is outside their chosen band, but they do not need to sell immediately. They are still investing every month, so they direct the next several contributions toward the stabilizing side first.
If the drift remains high after new contributions, they plan to rebalance in a tax-sheltered account before selling anything taxable. That order matters. The same risk fix can have a very different tax cost depending on which account is used.
Worked dollars: what “84% vs 75%” means
Say the portfolio is $200,000. Target is 75% stocks / 25% stabilizers; current mix is 84% / 16%.
- Current stocks: 0.84 × $200,000 = $168,000
- Target stocks: 0.75 × $200,000 = $150,000
- Overweight to trim (or redirect): $18,000
Path A — contributions only: if they invest $1,500/month and send all of it to stabilizers while stocks stay flat, it takes $18,000 ÷ $1,500 = 12 months to close the gap mechanically. If stocks keep rising, the gap can reopen — so they still need a review date.
Path B — one trim: sell $18,000 of stock funds inside a TFSA/RRSP (where available) and buy stabilizers. Mix returns to 75/25 immediately; tax drag is usually lighter than the same trade in a taxable account.
Scale matters. A $50,000 portfolio with the same 84% vs 75% drift only needs a $4,500 fix. A $500,000 portfolio needs $45,000. The percentage rule stays; the dollar action scales.
Canadian note: prefer tax-sheltered accounts (TFSA/RRSP) for sells when that matches the plan; in taxable accounts, contribution-first often wins until drift is extreme. Tax results still depend on your situation.
When selling makes sense
Selling can still be reasonable when the drift is large, the account is tax-sheltered, the position is concentrated, or the money is close to a real-life deadline. If a single stock or sector has become a life-changing percentage of your portfolio, waiting for perfect tax conditions can be its own risk.
Ask yourself: would I buy this much of it today if I had the cash? If the answer is no, trimming may be risk management rather than market timing.
A simple rebalancing routine
- Write down your target mix before looking at performance.
- Check the current mix across all accounts, not one account at a time.
- Use new contributions first where possible.
- Rebalance tax-sheltered accounts before taxable accounts when that fits your situation.
- Document the rule so the next review is easier.
Common mistakes
- Rebalancing too often: small moves can become busywork.
- Never rebalancing: winners can quietly turn a moderate plan into an aggressive one.
- Only checking one account: your total household portfolio is what matters.
- Ignoring taxes: selling in the wrong account can create avoidable friction.
- Calling fear a strategy: rebalancing should follow a rule, not a mood.
What to write in the plan
A rebalancing rule does not need to be complicated. A simple note can say: “Review twice a year. Use new contributions first. Rebalance if an asset class moves more than five percentage points from target. Consider tax impact before selling.” That is enough to reduce guesswork during both euphoric and scary markets.
The written rule also protects you from hindsight. If the trimmed asset keeps rising, you can remember why you acted: not because you predicted a top, but because the portfolio had moved beyond the risk level you meant to hold.
After a strong run, rebalancing is not a prediction that prices must fall. It is a reminder that your plan should control your risk, not the latest winner. Keep the process boring, rules-based, and tied to your actual goals.
To test how redirecting monthly contributions can fix drift without selling, use the Monthly Investment Calculator. For long-horizon balance checks after you reset the mix, use the Future Wealth Calculator.
Primary sources
CRA links for TFSA and RRSP context when selling inside registered accounts. Portfolio dollar examples are teaching cases only.
Disclaimer: Educational only — not investment advice. Tax rules, account types, risk tolerance, and time horizon can change the best rebalancing method.