Why it matters
A target allocation does not maintain itself. If stocks outperform bonds, their weight rises and the portfolio becomes riskier than originally chosen.
Rebalancing means selling, buying, or directing new cash to bring weights back toward target.
How it works
Common methods are calendar-based reviews or tolerance bands, such as acting when an asset class moves a set distance from target. The best method is one that is clear, tax-aware, and not triggered by every small move.
New contributions and withdrawals can often rebalance with less selling.
The essentials
- Rebalancing manages risk; it does not guarantee higher return.
- Set the rule before drift occurs.
- Use cash flows where possible.
- Consider tax and transaction costs in taxable accounts.
Use a contribution to restore the target mix
A portfolio with a 60% stock and 40% bond target now holds $7,200 in stocks and $3,800 in bonds. The owner has $1,000 of new money to invest.
Read the image as text
- Before contributing
- 65.5% / 34.5%$7,200 stocks + $3,800 bonds
- New money to bonds
- $1,000No sale is needed in this example
- After contributing
- 60% / 40%$7,200 stocks + $4,800 bonds
Example assumptions: A chosen target already exists, prices stay fixed during the calculation, and the $1,000 is genuinely available. No fees, tax, minimum purchase sizes, or account restrictions are modelled.
- Measure the drift
The total is $11,000. Stocks are $7,200 ÷ $11,000 ≈ 65.5%, above the 60% target.
- Try the new money first
Putting the full $1,000 contribution into bonds brings bonds to $4,800 and the total portfolio to $12,000.
- Check the new weights
$7,200 ÷ $12,000 = 60% stocks, and $4,800 ÷ $12,000 = 40% bonds. This particular contribution restores the target without selling anything.
New money can sometimes rebalance a portfolio on its own. The useful contribution amount depends on the actual drift and available cash, not a prediction of which asset wins next.
Your next-step checklist
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Write target weights and tolerance ranges.
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Review on a modest schedule.
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Look across all accounts as one portfolio.
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Record why each rebalance occurred.
Constant rebalancing can create unnecessary taxes, costs, and attention. A small drift is not automatically a problem.
Explore further, if useful
The essentials are above. Open a topic below when it helps answer your next question.
Another example: Restoring a 60/40 portfolio after a rally
A $100,000 portfolio starts with $60,000 in stocks and $40,000 in bonds. Stocks rise 20% while bonds are unchanged, producing $72,000 of stocks and a $112,000 total. Stocks now represent about 64.3%.
Returning to 60/40 requires moving roughly $4,800 from stocks to bonds, or using future cash flows to close the gap. The trade is driven by the target, not a claim that stocks are about to fall.
- New total
- $112,000
- Stock weight
- 64.3%
- Amount to redirect
- About $4,800
Rebalancing turns a target into a rule
Without a rule, rebalancing can become disguised market timing. Investors may rebalance after every small move when nervous, then avoid it after a large rally because the winning asset feels safest. Calendar reviews or tolerance bands create consistency.
Taxes and transaction costs matter. New contributions, dividends, and withdrawals can often move the portfolio toward target without selling appreciated assets in a taxable account.
A household with several accounts should rebalance at the combined level. One account can hold more bonds while another holds more stocks, provided the overall risk target and account-specific tax considerations remain intentional.
Choose the cheapest path back to target
Rebalancing does not have to begin with a sale. New contributions, distributions, interest, and planned withdrawals can all move the portfolio toward target weights. This cash-flow approach can reduce tax and trading costs, though it may be too slow after a large drift. Rank the available methods before placing trades.
Bands should be wide enough to ignore noise and narrow enough to prevent a meaningful change in risk. A five-percentage-point move has a different importance when the target is 50% than when the target is 5%, so some policies use relative thresholds or both absolute and relative tests. The exact rule is less important than writing it down, applying it across accounts, and checking tax consequences before execution.
Put the idea into a wider plan
Choose one rebalancing method in advance. A calendar rule checks the portfolio on set dates; a threshold rule acts when an asset moves outside a stated band; a hybrid checks periodically and trades only when a band is breached. The method matters less than applying it consistently. Very narrow bands can create unnecessary trading, while no rule allows yesterday's winner to determine tomorrow's risk.
Use the least disruptive tool first. Direct new contributions, dividends, or withdrawals toward underweight or overweight assets before selling. In taxable accounts, consider realized gains, losses, superficial-loss rules, and transaction costs. Rebalance the household portfolio as a whole when practical, including workplace plans. The aim is to restore the planned risk, not to predict which asset will lead next.
Does rebalancing increase returns?
It is primarily a risk-control process. It may add or subtract return depending on market patterns. Its dependable function is preventing allocation drift and requiring a disciplined sell-high, buy-low action relative to the chosen target.
How often should I rebalance?
Many plans use an annual or semi-annual review, threshold bands, or both. The best interval balances meaningful risk drift against taxes, costs, and effort. Daily monitoring usually adds noise without improving a long-term policy.
Should I rebalance during a market crash?
Follow the preset rule after confirming cash needs and that the target allocation remains suitable. Rebalancing can involve buying the asset that fell, which may feel uncomfortable. Do not add leverage or use emergency money simply to force the percentages back into place.