Rebalancing: How to Keep Your Portfolio on Target
Here’s the problem rebalancing solves: say you start with 70% stocks and 30% bonds. After a strong year for equities, you’re sitting at 80/20. You now carry more risk than you planned for. Rebalancing means selling some of the winners (stocks) and buying more of the laggards (bonds) to return to 70/30.
It feels counterintuitive — you’re trimming what’s working and adding to what isn’t. But that’s exactly the discipline that keeps your risk level consistent and systematically forces a “buy low, sell high” behavior.
Why Rebalancing Matters
Without rebalancing, a portfolio’s risk profile drifts with the market. A 60/40 portfolio left untouched through a bull market can easily become 80/20 — essentially doubling your equity risk. Then when the correction hits, you take a far bigger loss than your original plan anticipated.
Rebalancing isn’t primarily about maximizing returns. It’s about risk management. It keeps your portfolio aligned with your risk tolerance and time horizon so you’re not overexposed when conditions shift.
Common Rebalancing Strategies
| Strategy | How It Works | Best For |
|---|---|---|
| Calendar-based | Rebalance on a fixed schedule (quarterly, semi-annually, or annually) | Simplicity; set-it-and-forget-it investors |
| Threshold-based | Rebalance when any asset class drifts beyond a set band (e.g., ±5%) | More precise risk control; active investors |
| Cash flow rebalancing | Direct new contributions to underweight asset classes | Tax-efficient; accumulation phase investors |
| Hybrid | Check on a schedule, but only trade if thresholds are breached | Balanced approach; most common among advisors |
How to Rebalance: Step by Step
1. Review your current allocation. Log into your accounts and calculate the current percentage each asset class represents. If you hold investments across multiple accounts (brokerage, 401(k), Roth IRA), look at the total picture, not each account in isolation.
2. Compare to your targets. Identify which asset classes are overweight and which are underweight relative to your plan.
3. Execute trades. Sell overweight positions and buy underweight ones. Alternatively, direct new contributions and dividends toward underweight classes (the cash flow method) to minimize taxable events.
4. Consider tax implications. In taxable accounts, selling winners triggers capital gains tax. Prioritize rebalancing inside tax-advantaged accounts (IRAs, 401(k)s) where trades don’t create tax events. In taxable accounts, you can also pair rebalancing with tax-loss harvesting.
Rebalancing and Diversification
Rebalancing is the maintenance side of diversification. Diversification sets your initial mix; rebalancing preserves it. Without regular rebalancing, even a well-diversified portfolio gradually concentrates into whatever has performed best recently — which is exactly the wrong time to be overweight.
When Not to Rebalance
There are situations where rebalancing deserves a pause. If selling in a taxable account would trigger a large short-term capital gain, it may be worth waiting until the holding qualifies for long-term capital gains rates. Also, if transaction costs are high (some alternative investments or thinly traded securities), the cost of rebalancing can outweigh the benefit.
Key Takeaways
- Rebalancing restores your portfolio to its target asset allocation, keeping risk in check.
- It enforces a disciplined “buy low, sell high” pattern by trimming winners and adding to laggards.
- Annual or threshold-based rebalancing works well for most investors — more frequent trading adds costs, not value.
- Use tax-advantaged accounts for rebalancing trades when possible to avoid unnecessary tax bills.
Frequently Asked Questions
How often should I rebalance my portfolio?
Once or twice a year works for most investors. Alternatively, set a threshold (e.g., rebalance whenever any asset class drifts more than 5 percentage points from its target). The exact frequency matters less than having a consistent process.
Does rebalancing improve returns?
Not necessarily. Rebalancing is primarily a risk management tool. In a prolonged bull market, it can slightly drag on returns because you keep trimming equities. But it protects you from outsized losses when the market turns — which matters more for long-term compounding.
Should I rebalance across all accounts or within each account?
Think in terms of your total portfolio across all accounts. This gives you flexibility to hold tax-inefficient assets (like bonds) in tax-advantaged accounts and equities in taxable accounts, rebalancing across the whole picture for the best tax outcome.
What’s the difference between rebalancing and asset allocation?
Asset allocation is the initial strategic decision about how to split your money. Rebalancing is the ongoing maintenance that keeps those splits intact as markets move.