The Moment
Your portfolio has drifted from its target allocation.
This happens naturally as different asset classes grow at different rates. A portfolio that started at 80% stocks / 20% bonds in 2019 was probably closer to 90% / 10% by 2021 after the equity run-up. Rebalancing restores the risk profile you originally chose.
Decision Logic
When to rebalance Two approaches work: calendar rebalancing (once per year, regardless of drift) and threshold rebalancing (when any asset class drifts more than 5 percentage points from target). Research shows both produce similar outcomes. Calendar is simpler; threshold is more responsive to large market moves.
How to rebalance tax-efficiently In a tax-advantaged account (401k, IRA), rebalance freely — there are no tax consequences. In a taxable account, prefer rebalancing by directing new contributions to underweight assets rather than selling overweight ones. If you must sell, use tax-loss harvesting to offset gains.
What to rebalance to Rebalance back to your target allocation, not to a new allocation based on recent market performance. Chasing recent winners by adjusting targets is performance chasing in disguise.
Allocation Shift Planner
Shifting allocation in tax-advantaged accounts is free. In taxable, it triggers capital gains. This tool quantifies the tax friction.
20% of $500k shifted; ~40% embedded gain taxed at 15%
Educational illustration — not financial advice. Doesn't model the lots-by-lot picture (some lots may have losses, others gains). Strategies like specific-lot-identification can materially reduce tax cost.
Common Mistakes
Rebalancing too frequently. Monthly rebalancing in a taxable account generates unnecessary transaction costs and capital gains. Annual is sufficient for most investors.
Selling winners to buy losers without a plan. Rebalancing feels counterintuitive because you are selling what has done well. This is correct — it is disciplined risk management, not a prediction about future performance.
Ignoring tax consequences in taxable accounts. Selling appreciated assets to rebalance triggers capital gains taxes. Use new contributions and tax-advantaged accounts first.
What Changes the Answer
Account type. Rebalance freely in tax-advantaged accounts. Be tax-aware in taxable accounts.
Distance from retirement. As you approach retirement, the target allocation itself should shift toward more conservative assets. Rebalancing and glide-path adjustment are related but separate decisions.
Transaction costs. Most major brokerages now offer commission-free trading, which reduces the cost of rebalancing. If you pay per trade, threshold rebalancing (less frequent) is more cost-effective.
What to explore next
- →What should my target allocation be?
- →How do I rebalance without triggering capital gains?
- →Should I adjust my allocation as I get closer to retirement?
Frequently Asked Questions
How often should I rebalance my portfolio?
Once per year is sufficient for most investors. More frequent rebalancing generates transaction costs and, in taxable accounts, capital gains without meaningfully improving returns.
Does rebalancing improve returns?
Rebalancing does not reliably improve returns — it manages risk. By selling overweight assets and buying underweight ones, it prevents your portfolio from drifting to a higher-risk profile than you intended.
Should I rebalance during a market crash?
Yes. A market crash is one of the best times to rebalance because equities have become underweight relative to your target. Buying more equities during a crash is the disciplined response — it is rebalancing, not speculation.