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Guide

How Often Should You Rebalance Your Portfolio? Rules, Thresholds & a Worked Example

Updated · 7 min read · Independent — we never recommend specific funds or products

Quick answer

Check your portfolio once or twice a year and rebalance when any asset class has drifted about 5 percentage points from its target. Vanguard research found this kind of schedule strikes a reasonable balance between controlling risk and controlling costs. Rebalancing is mainly about keeping risk where you set it, not about boosting returns — and you can often do it with new contributions instead of selling.

Why rebalance at all

Markets move your allocation without asking. If stocks surge, they take up a larger share of your portfolio — and with it, more of your risk — even though you did nothing. A 60/40 mix left alone through a long bull market can turn into 75/25 without a single decision on your part. Rebalancing means selling a little of what has grown and buying what has lagged to restore your target. It is a risk-control habit: it keeps your portfolio as conservative or aggressive as you decided it should be.

Calendar vs threshold vs hybrid

MethodHow it worksTrade-off
CalendarRebalance on a fixed date — once or twice a year.Simple and habit-forming; may act when nothing has drifted, or wait while drift grows.
ThresholdRebalance only when an asset class drifts past a set band (commonly 5 percentage points).Acts only when needed; requires you to monitor.
HybridCheck on a calendar schedule, act only if a threshold has been crossed.Low effort and low cost — the most common practical choice.

Vanguard research has found that for broadly diversified stock-and-bond portfolios, annual or semiannual monitoring with rebalancing at 5% thresholds is a reasonable balance between risk control and cost, and that more frequent checks at tighter thresholds cost more without meaningfully improving risk-adjusted results. Our calculator's drift check uses the same 5-point convention.

A worked example

You start with $100,000 in a 60/40 portfolio: $60,000 in stocks, $40,000 in bonds.

  1. A year passes. Stocks rise 30% to $78,000; bonds rise 2% to$40,800. Total: $118,800.
  2. Check the weights. Stocks are now $78,000 ÷ $118,800 = 65.7%; bonds are 34.3%. Stocks have drifted 5.7 points above target — past the 5-point band.
  3. Compute the trade. A 60% stock target on $118,800 is $71,280. Sell$6,720 of stocks and buy $6,720 of bonds.
  4. Result. Stocks $71,280 (60%), bonds $47,520 (40%) — back on target.

You do not need to trade at all if you can restore balance another way: directing next year's contributions entirely to bonds would close much of that gap without selling anything.

Rebalancing without a big tax bill

  • Use tax-advantaged accounts first. Trades inside a 401(k), IRA, ISA, or similar wrapper generally do not trigger tax.
  • Route new money to the laggard. Contributions, dividends and interest can be pointed at the underweight asset class.
  • Fund withdrawals from the overweight class. If you are drawing income, sell what has grown.
  • Mind the cost of selling in taxable accounts. Realized gains can be taxable, so a wider band may make sense there. Tax rules vary by country — check yours.

Step-by-step checklist

  1. Write down your target allocation (percentages by asset class).
  2. Pick a schedule (e.g., every January and July) and a band (e.g., ±5 points).
  3. On review day, list current values and compute each class's actual percentage.
  4. If everything is inside the band, do nothing and note the date.
  5. If not, fix it with new money first, then with sales in tax-advantaged accounts, then (if needed) taxable accounts.

Do it in 30 seconds: enter your current mix in the “Already invested? Check your drift” section of thecalculator. It compares your holdings with your target and flags any asset class that has drifted 5 points or more.

See also: the 60/40 portfolio and401(k) asset allocation.

Frequently asked questions

How often should you rebalance your portfolio?

For most investors, checking once or twice a year and rebalancing when an asset class has drifted about 5 percentage points from target is a sensible balance. Vanguard research found no single optimal frequency, but that more frequent checks at tighter thresholds are more costly to implement without meaningfully better risk-adjusted results.

What is the 5% rebalancing rule?

The 5% rule says to rebalance when any asset class is more than 5 percentage points away from its target weight — for example, when a 60% stock target has drifted to 65% or 55%. Some investors use a relative version, rebalancing when an allocation is off by 25% of its target weight.

Does rebalancing increase returns?

Not reliably. The main benefit of rebalancing is risk control: it keeps your portfolio at the level of risk you chose instead of letting winners quietly take over. Research has found risk-adjusted returns do not differ meaningfully across common rebalancing strategies.

How do I rebalance without paying taxes?

Rebalance inside tax-advantaged accounts first, where trades generally are not taxed. In a taxable account, direct new contributions, dividends and interest toward the underweight asset class, or fund withdrawals from the overweight one, so you may not need to sell at all.

Should I rebalance during a market crash?

A threshold-based rule will often tell you to buy stocks after they fall, which feels uncomfortable but restores your intended risk level. If you have a written rule, following it removes the emotion; if you would abandon the plan, revisit whether your target mix matches your true risk tolerance.

Sources & further reading

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This guide is general education, not financial, investment, tax, or legal advice, and it does not recommend any specific security, fund, or product. Example percentages are illustrations, not recommendations for you. Past performance does not guarantee future results. Consider speaking with a licensed professional before making investment decisions. See ourmethodology anddisclaimer.