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How to rebalance your portfolio in 2026: when, why, and how
When markets run, your allocation drifts — and with it, your risk level. Rebalancing once a year takes 20 minutes and keeps your plan on track.
You chose a 70/30 stock/bond split for a reason — it matched your risk tolerance and time horizon. After a 20% stock rally, you might be sitting at 78/22 without touching anything. That extra stock exposure means extra volatility in the next downturn. Rebalancing fixes it.
Why allocation drifts
Different asset classes grow at different rates. When US stocks return 25% and bonds return 4%, your equity percentage balloons. Left unchecked, a portfolio that started at 70% stocks can easily reach 85–90% after a multi-year bull market — taking on risk you never intended.
| Year | Target | After drift (no rebalancing) | Risk change |
|---|---|---|---|
| Start | 70% stocks / 30% bonds | 70% / 30% | — |
| Year 3 | 70% / 30% | 78% / 22% | +8% equity, higher vol |
| Year 7 | 70% / 30% | 88% / 12% | Effectively aggressive growth |
When to rebalance
Two common triggers — use whichever fits your style:
- Calendar (annual or semi-annual): Review allocation every January. Simple, consistent, easy to automate as a reminder.
- Threshold (5% drift): Rebalance whenever any asset class drifts more than 5 percentage points from its target. More responsive, slightly more trades.
Vanguard's research finds annual rebalancing and 5%-threshold rebalancing produce nearly identical risk-adjusted outcomes. The method matters less than doing it consistently.
Three ways to rebalance
Method 1: Rebalance inside tax-advantaged accounts first (most tax-efficient)
Your 401(k) and IRA are tax-deferred or tax-free. Selling overweighted funds and buying underweighted ones inside these accounts creates zero taxable events. If your overall allocation drifts, fix it by adjusting holdings in tax-advantaged accounts first — you may not need to touch taxable accounts at all.
Method 2: Direct new contributions to underweighted assets
If you're still in accumulation phase, you can rebalance without selling anything. When you make your monthly 401(k) contribution or IRA deposit, direct the entire contribution to underweighted assets. Over time this corrects the imbalance gradually and efficiently.
Method 3: Sell overweighted assets in taxable accounts
If methods 1 and 2 aren't enough, sell in your taxable brokerage account. Minimize tax drag by:
- Selling positions with a tax loss first (realizes a loss you can deduct)
- Preferring to sell long-term holdings (taxed at 0%, 15%, or 20%) over short-term (taxed at ordinary income rates)
- Selling only enough to bring the portfolio back to within 3–5% of target
Step-by-step: how to actually do it
Most major brokerages let you view a consolidated view of your portfolio across all accounts. Here's the process:
- List all your holdings and their market values.Include 401(k), IRA, and taxable accounts. Most brokerages show this on the “Portfolio” or “Holdings” page.
- Calculate current allocation percentages. Add up total in US stocks, international stocks, bonds, and other categories. Divide each by the total portfolio value.
- Subtract from your target.If target is 60/30/10 (US stocks/bonds/international) and you're at 70/22/8, US stocks are +10% over, bonds -8%, international -2%.
- Rebalance inside 401(k)/IRA first.Go to your 401(k)'s “change investment options” or “rebalance” tool. Sell overweighted funds, buy underweighted ones.
- Use new contributions to fill remaining gaps. Direct your next IRA contribution or 401(k) increase to the underweighted category.
- Only sell in taxable accounts if still needed. Focus on tax-loss harvesting opportunities and long-term held positions.
Rebalancing vs. target-date funds
Target-date funds (e.g., Vanguard Target Retirement 2050) rebalance automatically to a built-in glide path. If you invest in one of these and nothing else, you don't need to rebalance — the fund handles it internally at low cost.
The limitation: a target-date fund assumes a specific retirement date and uses a standardized glide path. If you want a custom allocation (e.g., more international, more bonds than the fund's glide path), you need to build and rebalance your own mix.
For more on the basics, see how to start investing and index funds vs. ETFs.
Automated rebalancing tools
Several platforms offer automatic rebalancing so you never have to do it manually:
- Fidelity Go: automated managed account, free under $25K. Rebalances when allocation drifts ±5%.
- Schwab Intelligent Portfolios: $0 fee automated account that rebalances automatically. Includes ETF expense ratios and a cash allocation.
- Betterment and Wealthfront (robo-advisors): sophisticated tax-loss harvesting + automatic rebalancing at 0.25% AUM fee. Good for taxable accounts where tax optimization matters.
The bottom line
Set a rebalancing reminder for January every year. Log in, check if any allocation drifts more than 5% from your target, and fix it — first inside your 401(k)/IRA, then via new contributions, then in taxable only if needed. The whole process takes 20–30 minutes and keeps your risk level matching your actual plan.
Related reading
- How to start investing — picking your target allocation in the first place.
- Index funds vs. ETFs — the building blocks of a diversified portfolio.
- 401(k) contribution limits 2026 — maximize contributions before rebalancing trades in taxable.
- Roth vs. traditional IRA — which tax-advantaged account to prioritize for holding overweighted assets.
- Tax-loss harvesting — turning losses in taxable accounts into tax savings.
Frequently asked questions
- How often should I rebalance my portfolio?
- The research suggests calendar rebalancing (annually or semi-annually) and threshold rebalancing (when any asset class drifts more than 5 percentage points from its target) produce similar outcomes. Annual rebalancing in January works well for most investors. More frequent rebalancing doesn't meaningfully improve returns and increases transaction costs and potential tax drag.
- What triggers a rebalance — time or drift?
- Either can work. Threshold-based rebalancing (rebalance when any allocation drifts more than 5%) is theoretically superior because it responds to actual market conditions rather than arbitrary calendar dates. In practice, annual calendar rebalancing is simpler and performs nearly as well for most buy-and-hold investors. Use whichever system you'll actually follow consistently.
- Does rebalancing hurt returns?
- Rebalancing slightly reduces long-run returns during prolonged bull markets because it trims the outperforming asset (usually equities). But it reduces volatility and drawdown — and forces you to buy low / sell high systematically. Vanguard research finds rebalancing costs about 0.1–0.2% per year in returns while reducing portfolio volatility by 10–15%. For most investors, the risk reduction is worth it.
- How do I rebalance without triggering a big tax bill?
- In taxable accounts: (1) use new contributions to buy underweighted assets, (2) redirect dividends and distributions to underweighted assets, and (3) sell only when the tax cost is outweighed by rebalancing benefit. Always rebalance inside tax-advantaged accounts (401k, IRA) first — trades there are tax-free. Use tax-loss harvesting opportunities to offset gains when you do sell in taxable accounts.
- What if I don't rebalance at all?
- Your portfolio gradually becomes riskier over time. In a 10-year bull market for equities, a starting 70/30 stock/bond portfolio can drift to 90/10 without rebalancing. That worked great until 2022 when both stocks and bonds fell — a 90/10 portfolio lost ~25% while a rebalanced 70/30 would have lost ~18%. Unmanaged drift means you're taking more risk than your plan intended.
- Can I rebalance a 401(k) without taxes?
- Yes. 401(k) accounts are tax-deferred — buying and selling inside the account doesn't trigger capital gains. You can freely sell overweighted funds and buy underweighted ones. Check for any redemption fees on fund trades (some target-date funds have short-term redemption fees if sold within 30–60 days of purchase). Most index funds inside 401(k)s have none.