Portfolio Rebalancing: Complete Guide on When and How to Do It

Portfolio rebalancing guide: calendar vs threshold-based methods, common mistakes, and practical tools for Indonesian passive investors.

Published: February 19, 2026 • Last reviewed: February 19, 2026

Note: This article discusses Indonesian financial products and markets. The principles apply globally, though specific products, regulations, and tax treatments vary by country.

January 2020: You set a portfolio of 60% stocks / 40% bonds. Total Rp 100 million.

December 2025: Stocks rose 80%, bonds rose 25%. Portfolio is now 68% stocks / 32% bonds.

Is this a problem? Or is it actually good because stocks profited a lot?

The answer: This is a problem. Your portfolio is now riskier than you planned. When a crash comes, you could lose more than your risk tolerance allows.

This is why rebalancing matters — and why passive investing doesn’t mean “set and forget” completely.

But there’s one important routine you must not forget: rebalancing.

Rebalancing is the process of returning your portfolio to its target allocation after market movements change your asset proportions.

This isn’t about market timing or chasing maximum returns. It’s about risk management and ensuring your portfolio remains aligned with your risk tolerance and investment goals.

The Anatomy of Drift: How Portfolios Shift

Let’s look at a real example of how portfolios “drift” from their target:

Year 2020: Your Starting Portfolio

You start with a target allocation:

60% Stock Mutual Funds (IHSG): Rp 60 million
30% SBN (Surat Berharga Negara — Government Securities): Rp 30 million
10% Digital Gold: Rp 10 million
Total: Rp 100 million

Year 2025: After 5 Years Without Rebalancing

Assuming 5-year historical returns:

Stocks (IHSG): +60% total → Rp 96 million
SBN: +35% total → Rp 40.5 million
Gold: +45% total → Rp 14.5 million
Total: Rp 151 million

New allocation:

Stocks: 63.6% (from target 60%)
SBN: 26.8% (from target 30%)
Gold: 9.6% (from target 10%)

What’s the problem?

Portfolio is riskier — Stock proportion increased, volatility increased
Not according to plan — When you set 60/30/10 target, it was based on your risk tolerance. Now the risk profile is different.
Missed opportunity — You could sell stocks at high prices, buy underperforming SBN (automatic buy low, sell high)

This is why rebalancing matters.

Two Rebalancing Philosophies: When Should You Do It?

1. Calendar-Based Rebalancing

How it works: Rebalance at fixed time intervals, regardless of how large the drift.

Interval	Advantages	Disadvantages
Monthly	Portfolio always close to target	Too frequent, could be over-rebalancing
Quarterly	Fairly responsive	Still somewhat frequent for passive investors
Semi-annually	Balance between effort and control	Popular choice
Annually	Very simple, low maintenance	Drift can be quite large within a year

nabung.id recommendation: Semi-annually (every 6 months) or annually.

Implementation example:

Set calendar reminder: every January 1 and July 1
Check portfolio, calculate current allocation vs target
Rebalance if drift >3-5%

Main advantage: Simple, no need for constant monitoring, clear schedule.

2. Threshold-Based Rebalancing

How it works: Rebalance only if allocation deviates more than a certain threshold.

Example: Target allocation: 60% stocks / 30% SBN / 10% gold
Threshold: ±5%

Asset	Target	Threshold Band	Trigger Rebalancing If…
Stocks	60%	55% - 65%	< 55% or > 65%
SBN	30%	25% - 35%	< 25% or > 35%
Gold	10%	5% - 15%	< 5% or > 15%

Advantage: More efficient—no rebalancing if drift is small (less than 5%).

Disadvantage: Requires more frequent monitoring to detect when threshold is crossed.

When suitable: If you have many assets (5+ asset classes) or a large portfolio (hundreds of millions to billions of rupiah).

Two Rebalancing Methods: Buy-Sell vs New Contributions

Method 1: Sell Winners, Buy Losers

How it works:

From the example above (Rp 151 million portfolio, 63.6/26.8/9.6 allocation), to return to 60/30/10:

New targets:

Stocks: 60% × Rp 151 million = Rp 90.6 million
SBN: 30% × Rp 151 million = Rp 45.3 million
Gold: 10% × Rp 151 million = Rp 15.1 million

Actions:

Sell stock mutual fund: Rp 96 million - Rp 90.6 million = Rp 5.4 million
Buy SBN: Rp 45.3 million - Rp 40.5 million = Rp 4.8 million
Buy gold: Rp 15.1 million - Rp 14.5 million = Rp 0.6 million

Advantages:

Portfolio immediately returns to target
Discipline of “sell high, buy low”

Disadvantages:

In other markets (US), this could trigger capital gains taxes
For individual stocks, there are transaction costs

In Indonesia: For mutual funds, there’s no capital gains tax and no buy/sell fees on platforms like Bibit/Bareksa. So this method is very effective.

Read: NPWP for Investing

Method 2: Use New Contributions for Rebalancing

How it works: Instead of selling, direct your monthly regular investments to assets that are under-allocated.

Example:

Current portfolio: 63.6% stocks / 26.8% SBN / 9.6% gold (total Rp 151 million)
Target: 60/30/10
Regular investment: Rp 5 million/month

Strategy:

Calculate difference: SBN is short 3.2%, gold is short 0.4%
For the next few months, allocate more to SBN and gold until proportions are balanced again

Months 1-3:

Rp 3 million → SBN
Rp 1.5 million → Gold
Rp 0.5 million → Stocks

After 3 months (total investment Rp 15 million), portfolio returns to approximately 60/30/10.

Advantages:

No need to sell anything — simpler
No tax events (though this isn’t relevant for mutual funds)
Suitable for investors with regular monthly investments

Disadvantages:

Slower — takes several months to return to target
Not practical if drift is very large or there are no regular contributions

Recommendation: Use this method for small drift (3-5%), use buy-sell method for large drift (>7%).

Rebalancing with Multiple Goals: Advanced Strategy

Most investors have more than one investment goal:

Emergency fund (liquid, safe)
House down payment (3-5 years)
Children’s education (10-15 years)
Retirement (20-30 years)

Should all goals be rebalanced with the same allocation? No!

Strategy: Rebalancing Per Bucket

Bucket 1: Emergency Fund (Time Horizon: <1 Year)

Allocation: 100% money market/deposits
Rebalancing: Not needed — allocation doesn’t shift

Bucket 2: House Down Payment (Time Horizon: 3-5 Years)

Allocation: 30% stocks / 70% bonds (conservative)
Rebalancing: Every 6 months, gradually reduce stocks as target date approaches

Bucket 3: Children’s Education (Time Horizon: 12 Years)

Allocation: 70% stocks / 30% bonds (growth-oriented)
Rebalancing: Annual, transition to more conservative every 3 years
Glide path: Years 1-8 (70/30) → Years 9-11 (50/50) → Years 12-15 (20/80)

Common Mistakes in Rebalancing

1. Never Rebalancing at All

Problem: Portfolio drifts drastically, risk uncontrolled.

Extreme example: Target 60/40, after 10 years without rebalancing becomes 85/15. During a market crash, portfolio drops much deeper than your risk tolerance.

Solution: Set automatic reminder at least once a year.

2. Rebalancing Too Frequently

Problem: Over-rebalancing. Every week checking portfolio, panicking because of 1% drift, immediately buying and selling.

Why it’s bad: Retail investors waste time and energy for minimal results. Plus, it can become “closet trading” that undermines passive investing discipline.

Solution: Set a minimum threshold (e.g., 5%) or fixed schedule (6 months/1 year). Outside of that, don’t touch your portfolio.

Read: Fear of Investing: Overcoming Market Anxiety

3. Rebalancing with Emotions (Disguised Market Timing)

Example: Your portfolio is 63% stocks (target 60%), but you think “stocks will keep rising, let’s just leave it without rebalancing.”

Or the opposite: “Stocks are high, looks like a crash is coming. I’ll sell all stocks, buy bonds first.”

Problem: This isn’t rebalancing, this is market timing. You’re no longer passive investing, but trying to predict market direction.

Solution: Follow mechanical rules. If drift >5%, rebalance. Regardless of how you feel about the market.

4. Ignoring Costs and Taxes

In Indonesia, mutual funds are exempt from capital gains tax and have no buy/sell fees. But for other assets:

Stocks:

Sell transaction tax: 0.1% (with NPWP)
Bid-ask spread can be significant for small stocks

SBN:

Difficult to sell before maturity (low liquidity in secondary market)
Better to hold until maturity, rebalance with new contributions

Physical gold:

Buy-sell spread can be 5-10%
Not practical for rebalancing, better to use digital gold or gold mutual funds

Read: Gold Investment: Physical, Digital, or Mutual Fund

5. Rebalancing Without Updating Target Allocation

Problem: You set 80/20 target at age 25 (aggressive). Now you’re 50, should be more conservative (e.g., 50/50), but you’re still rebalancing to 80/20.

Solution: Review target allocation every 3-5 years or when there’s a major life event (marriage, having children, approaching retirement).

Read: Investment Policy Statement: Your Financial Blueprint

Tools and Automation for Rebalancing

1. Manual Spreadsheet (Google Sheets/Excel)

Simple template:

Asset	Current Value	Current Proportion	Target	Difference	Action
Stocks	Rp 96 million	63.6%	60%	+3.6%	Sell Rp 5.4 million
SBN	Rp 40.5 million	26.8%	30%	-3.2%	Buy Rp 4.8 million
Gold	Rp 14.5 million	9.6%	10%	-0.4%	Buy Rp 0.6 million

Formulas:

Current Proportion: = Value / TOTAL
Difference: = Current Proportion - Target
Action: = (Target × TOTAL) - Current Value

2. Auto-Rebalancing Feature on Platforms (If Available)

Some global robo-advisors (like Betterment, Wealthfront in the US) have auto-rebalancing features. In Indonesia (2026), platforms like Bibit and Ajaib are starting to offer similar features for packaged portfolios.

How it works: You set target allocation, system automatically rebalances at certain intervals.

Advantages: Fully automatic, no thinking required.

Disadvantages: Less flexible for custom strategies (e.g., multiple buckets).

3. Portfolio Tracking Apps

Global examples: Personal Capital, Morningstar Portfolio Manager
Indonesia examples: Stockbit (for stocks), or manual tracking in Notion/Spreadsheet

Important features:

Input all assets (mutual funds, stocks, SBN, gold)
View real-time allocation
Notification if drift exceeds threshold

Rebalancing Checklist: Practical Steps

Every 6 Months (or Annually):

Record current value of all assets
- Mutual funds: check on Bibit/Bareksa/IPOT
- SBN: check on purchase platform (e.g., SBNI on Tokopedia)
- Stocks: check on your broker
- Gold: check on Pegadaian Digital/Tokopedia
Calculate current proportions
- Total portfolio: Sum all assets
- Each proportion: Asset value / Total
Compare with target allocation
- Write your target (e.g., 60/30/10)
- Calculate difference (drift)
Decide whether rebalancing is needed
- If drift <3%: No action needed
- If drift 3-5%: Use new contributions for rebalancing
- If drift >5%: Execute buy-sell
Execute rebalancing
- For mutual funds: Sell excess, buy shortfall (free, no tax)
- For SBN: Don’t sell before maturity, rebalance with new contributions
- For stocks/gold: Consider transaction costs
Record date and rebalancing results
- Documentation: when you rebalanced, what you did
- Evaluation: does your strategy still align with your goals?
Set reminder for next rebalancing

Conclusion: Rebalancing Is Discipline, Not Optimization

Rebalancing is not about:

Chasing maximum returns
Market timing
Showing off your investment skills

Rebalancing is about:

Risk management — keeping portfolio aligned with your risk tolerance
Discipline — sell when up, buy when down (contrary to emotions)
Simplicity — mechanical strategy that doesn’t require market predictions

nabung.id recommendations:

Rebalance at least once a year (or every 6 months)
Use ±5% threshold as trigger
Take advantage of Indonesia’s benefits: Mutual funds are tax-free and transaction-free for rebalancing
Use new contributions for small drift, buy-sell for large drift
Review target allocation every 3-5 years according to life changes
Don’t over-rebalance — this is passive investing, not day trading

Rebalancing is the only moment you “touch” your portfolio in passive investing. Do it with discipline, then return to your life routine.

To understand how rebalancing integrates into a comprehensive passive investing strategy, read: Asset Allocation: The Foundation of a Passive Portfolio.

References

Vanguard Group. (2015). Best Practices for Portfolio Rebalancing. Valley Forge, PA: Vanguard Research.
Gobind Daryanani. (2008). “Opportunistic Rebalancing: A New Paradigm for Wealth Managers”. Journal of Financial Planning, 21(1), 48-61.
Undang-Undang Republik Indonesia Nomor 36 Tahun 2008 tentang Pajak Penghasilan, Pasal 4 ayat (3) huruf i (tax exemption for mutual funds).
Jaconetti, C. M., Kinniry, F. M., & Zilbering, Y. (2010). Best Practices for Portfolio Rebalancing. Vanguard Investment Counseling & Research.
Plaxco, L. M., & Arnott, R. D. (2002). “Rebalancing a Global Policy Benchmark”. Journal of Portfolio Management, 28(2), 9-22.
Otoritas Jasa Keuangan (OJK — Financial Services Authority). (2024). Statistik Reksa Dana Indonesia. Jakarta: OJK. (Data for mutual fund transaction cost analysis)

Disclaimer: This article is for educational purposes only and does not constitute investment advice. Always do your own research and consult with a licensed financial advisor before making investment decisions.