Rebalancing

The plain answer

Rebalancing means bringing your portfolio back to the percentages in your investment plan. If your target is 70% stocks and 30% bonds, market movements may eventually push the mix to 76% stocks and 24% bonds. Rebalancing restores the amount of risk you intended to take.

You can rebalance on a calendar, such as once a year, or when an asset class moves beyond a chosen threshold. The best method is one you can follow consistently without creating unnecessary trades, costs, or taxes.

Rebalancing is not a way to predict which investment will perform best next. It is a risk-control process based on your asset allocation.

How it actually works

Your target percentages give you a reference point. As prices change, each holding becomes a larger or smaller share of the portfolio. This movement is called portfolio drift.

There are two common ways to decide when to act:

• Calendar rebalancing: Review the portfolio on a regular schedule, often every six or twelve months. Trade only if the mix has moved enough to matter.
• Threshold rebalancing: Act when an allocation crosses a preset boundary, such as 5 percentage points away from its target. A 60% stock target might trigger action below 55% or above 65%.

A calendar rule is easy to remember and limits how often you check. A threshold rule responds directly to drift, but it requires monitoring and can lead to more trades in volatile markets. You can combine them by checking once or twice a year and trading only when a threshold has been crossed.

Rebalancing does not always require selling. New contributions, dividends, and interest can be directed toward underweight investments. Withdrawals can come from overweight investments. These cash-flow methods may move the portfolio toward its target with fewer tax consequences.

When trades are needed, consider the full portfolio across all accounts. Rebalancing inside a tax-advantaged account generally does not create a current capital gain or loss. Selling appreciated investments in a taxable account can create a tax bill. Transaction fees, bid-ask spreads, and restrictions on certain funds can also make frequent or very precise rebalancing costly.

What this means for you

Start with written targets for stocks, bonds, and any other asset classes you own. If you are still deciding on that mix, review stocks vs. bonds before choosing a rebalancing rule.

Pick a review schedule and a threshold before markets become stressful. For example, you might review every six months and rebalance only when a major asset class is more than 5 percentage points from its target. The specific threshold matters less than having a reasonable rule you will apply consistently.

At each review:

1. Calculate each asset class as a percentage of the entire portfolio.
2. Compare the current percentages with the targets and thresholds.
3. Use contributions, distributions, and withdrawals first when practical.
4. Prefer tax-advantaged accounts for necessary trades when that fits the overall plan.
5. Check taxes, trading costs, and account restrictions before placing orders.

Rebalancing back to a target can mean selling an investment that recently performed well and buying one that performed poorly. That may feel uncomfortable, but it is the mechanism that keeps your portfolio aligned with your chosen risk level.

Common mistakes

• Rebalancing because of a market forecast instead of following a preset rule.
• Checking too often and reacting to small changes that do not alter portfolio risk meaningfully.
• Looking at each account separately instead of treating all accounts as one portfolio.
• Selling appreciated assets in a taxable account without estimating the capital-gains impact.
• Trying to reach exact percentages when a reasonable range would reduce trading.
• Forgetting to update the target after a real change in goals, time horizon, or ability to take risk.

Related pages

• Portfolio drift
• Asset allocation
• Stocks vs. bonds