The Short Answer

Portfolio rebalancing is the process of bringing your investments back to their target allocation after market movements cause them to drift. It helps keep risk at the level you intended and imposes a discipline of trimming assets that have grown and adding to those that have lagged. Common approaches include rebalancing on a schedule, such as annually, when allocations move outside predefined ranges, or a combination of both. The best approach balances risk control with costs and taxes.

Why Does a Portfolio Drift?

Different investments grow at different rates. During a strong stock market, the equity portion of a portfolio rises as a share of the total, gradually increasing risk beyond what was originally intended. After a sharp decline, the reverse can occur. Without rebalancing, a portfolio’s allocation is effectively determined by recent market performance rather than by your goals.

Consider a portfolio designed with 60% stocks and 40% bonds. After several years of strong equity returns, it might drift to 70% stocks, exposing the investor to larger potential losses than they intended to accept.

What Are the Common Rebalancing Approaches?

Calendar-Based Rebalancing

The portfolio is reviewed and rebalanced at set intervals, such as quarterly, semiannually, or annually. This approach is simple and predictable, though it may result in trades when drift is minimal or miss significant drift between reviews.

Threshold-Based Rebalancing

The portfolio is rebalanced when an asset class moves outside a set range around its target, such as five percentage points, or a percentage of the target weight. This approach responds to market movements rather than the calendar and can reduce unnecessary trading.

Hybrid Approaches

Many investors review on a regular schedule but trade only when allocations fall outside tolerance ranges. This combines discipline with efficiency.

Research has generally found that the specific frequency matters less than having a consistent, disciplined approach. Your rebalancing policy can be documented in an investment policy statement, as described in our resource on investment policy statements for families.

How Can You Rebalance Tax-Efficiently?

In taxable accounts, selling appreciated investments to rebalance can trigger capital gains taxes. Several techniques can help:

  • Use cash flows: Direct new contributions, dividends, and interest toward underweight assets, and fund withdrawals from overweight assets.
  • Rebalance in tax-advantaged accounts: Trades within IRAs and 401(k)s do not create current tax liabilities.
  • Harvest losses: Pair rebalancing sales with tax-loss harvesting to offset gains.
  • Use charitable giving: Donate appreciated shares from overweight positions instead of cash.
  • Consider tolerance ranges: Wider ranges in taxable accounts can reduce the frequency of taxable trades.

Our resources on tax-loss harvesting and asset location discuss these strategies in more detail.

Does Rebalancing Improve Returns?

The primary purpose of rebalancing is risk management, not return enhancement. In some periods, rebalancing may modestly improve returns by systematically selling high and buying low. In others, particularly during long trends, it may reduce returns compared to letting winners run. What rebalancing consistently does is keep the portfolio aligned with the level of risk you chose.

What About Rebalancing During Volatile Markets?

Rebalancing can feel uncomfortable during market stress because it often means buying assets that have recently declined. That discipline is part of its value. Having a predetermined rebalancing policy helps reduce emotional decision-making when markets are volatile. Newport’s article on market uncertainty offers related perspective.

The Takeaway

Rebalancing helps ensure your portfolio reflects your goals rather than recent market movements. A consistent, tax-aware approach, documented in advance, supports disciplined decision-making through changing markets. As part of Newport’s private wealth portfolio management, our investment team monitors client portfolios against their target allocations.

This article is provided for educational purposes only and is not individualized investment, tax, or legal advice. Please consult qualified professionals about your specific circumstances and review our disclosures.