Rebalancing Meaning: What is Portfolio Rebalancing?
Learn what rebalancing means, why it matters, and how to do it — all in one guide.
ETF Rebalancing Editorial Team · Reviewed 2026-07-26
Rebalancing is the process of restoring your portfolio's asset allocations back to their target weights when market movements cause them to drift — by selling overweight assets and buying underweight ones.
What is Rebalancing?
Portfolio rebalancing is the process of realigning asset weights that have drifted from target allocations. For example, if a 60/40 stock-bond portfolio has shifted to 70/30 due to stock gains, you would sell some stocks and buy bonds to restore the original ratio.
As markets move, your asset allocations naturally shift. Without rebalancing, your portfolio can become overly concentrated in certain assets, taking on unintended risk. Regular rebalancing is the key strategy to address this.
5 Reasons Why Rebalancing Matters
Risk Management
When allocations drift from targets, your portfolio's risk level changes too. Rebalancing maintains your intended risk profile.
Prevent Emotional Trading
Rule-based buying and selling prevents fear and greed-driven decisions during market volatility.
Rule-based Drift Correction
The process trims assets above their target and adds to assets below it. It does not guarantee that trades occur at market highs or lows.
Manage Concentration and Volatility
Keeping one asset from dominating the portfolio helps maintain the intended risk level, but it does not guarantee higher returns.
Maintain Investment Discipline
Consistently maintaining your original strategy and allocation helps achieve long-term investment goals.
Rebalancing Methods: Calendar vs Band
Calendar Rebalancing
Executed at fixed intervals (monthly, quarterly, or annually). Simple and easy to maintain discipline.
Pros: Simple, minimizes emotional interference
Cons: May trigger unnecessary trades
Band Rebalancing
Triggered only when allocations drift beyond ±5-10% from target. Reduces unnecessary trades while maintaining balance.
Pros: Saves transaction costs, efficient
Cons: Requires monitoring
Hybrid Approach (Recommended)
Combines quarterly reviews with band conditions. Keeping the review schedule and the execution trigger separate reduces unnecessary trades while still reacting quickly to large drifts.
How to Rebalance in 5 Steps
- 1
Step 1: Set Target Allocations
Define target percentages for each asset class based on your investment goals and risk tolerance. (e.g., 60% stocks, 30% bonds, 10% cash)
- 2
Step 2: Check Current Allocations
Review the current market value of your holdings and calculate the actual percentage each asset represents.
- 3
Step 3: Assess Drift
Determine if the difference between target and current allocations exceeds your rebalancing threshold (e.g., ±5%).
- 4
Step 4: Execute Trades
Sell overweight assets and buy underweight ones. If you have new cash, prioritize buying underweight assets to reduce transaction costs.
- 5
Step 5: Record and Repeat
Log your rebalancing activity and set the next review date. Consistently following your schedule — quarterly or annually — is key.
Follow along with calculator screenshots
Calculator Guide
Review the individual and group portfolio flows screen by screen.
Screen 1
Open guide and empty state
Review the individual portfolio flow even when no portfolio exists or data is still loading.
Details
Sequence
- Review the individual portfolio flow even when no portfolio exists or data is still loading.
- Use the highlighted mobile controls in the order shown on the image.
- Confirm the selected portfolio or group before moving to the next step.
What to verify
- This step affects later rebalance calculations.
- Review names, weights, quantities, and cash before continuing.
- If something looks wrong, return to the previous input and correct it.
Watch out
- The calculator does not place brokerage orders.
- Verify brokerage prices, executable quantities, taxes, and cash before real trades.
Setting Your Rebalancing Frequency
The right frequency varies by individual, but quarterly to annual rebalancing is most common.
- For more volatile assets, set wider bands (e.g., ±10%)
- Avoid small, frequent trades; prefer adjusting with new cash inflows
- In taxable accounts, minimizing taxable events is essential
- Use tax-advantaged accounts (IRA, 401k) to rebalance with less tax burden
Tax and Cost Considerations
When rebalancing, consider total transaction costs including fees, spreads, and taxes. Set thresholds to reduce excessive trading, and in taxable accounts, consider tax-loss harvesting and holding period taxation.
- •Taxable accounts: Sales may trigger capital gains tax → reduce frequency or use cash inflows instead
- •Tax-advantaged accounts (IRA/401k): Trades may not create the same immediate tax event as a taxable account, but contribution, withdrawal, and investment rules still apply
- •Fees/spreads: Higher trading frequency means higher costs → use band method to minimize unnecessary trades
Worked Example: $10,000 Portfolio
Take a $10,000 portfolio with a 60/40 stock-bond target that has drifted after a market move, and apply the formula directly.
| Asset | Target (Amount) | Current Value (Weight) | Adjustment | After Rebalance |
|---|---|---|---|---|
| US Stocks (VTI) | 60% ($6,000) | $6,800 (68%) | Sell $800 | $6,000 (60%) |
| US Bonds (AGG) | 40% ($4,000) | $3,200 (32%) | Buy $800 | $4,000 (40%) |
The adjustment equals the target value (total × target weight) minus the current value. To avoid selling, you could instead add about $1,333 of new cash to bonds — the total grows to $11,333, stocks land at exactly 60%, and no capital gains tax is triggered.
Frequently Asked Questions
What does rebalancing mean exactly?
Rebalancing means restoring your portfolio's asset weights back to the original target allocation when they have drifted. You trim overweight assets or add to underweight ones to restore your intended risk level.
When and how often should I rebalance?
Start applying it consistently right after setting your target allocations. Quarterly to annual reviews are most common, and executing trades only when weights drift 5-10%p beyond target (a band condition) helps avoid unnecessary trading.
Can I rebalance using only new cash inflows?
Yes. Buying underweight assets with new cash can bring your portfolio back to target allocations while reducing tax and fee burdens.
What is the difference between band and calendar rebalancing?
Calendar rebalancing is done at fixed intervals (e.g., quarterly or annually), while band rebalancing triggers only when allocations drift beyond a set range. Use wider bands (e.g., ±10%) for volatile assets, and combining both methods reduces excessive trading while maintaining balance.
How should I account for taxes and fees?
In taxable accounts, rebalancing trades can create taxable events. Set thresholds that factor in fees and spreads, or rebalance using new cash inflows to minimize tax impact.
Does rebalancing always improve returns?
Not always. Its primary purpose is volatility management and risk control rather than maximizing returns, and over the long term it significantly reduces emotional trading.
Is index rebalancing (S&P 500, KOSPI 200) the same as rebalancing my portfolio?
Both restore target weights, but they apply to different things. Index rebalancing changes index constituents and weights, while personal portfolio rebalancing restores your own stock, bond, and cash weights back to your target allocation.
Do ETF portfolios need rebalancing too?
Yes, ETF allocations drift with market movements just like individual stocks, so regular rebalancing is necessary.
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