Contents
Definition
Rebalancing is the process of realigning portfolio weights back to a target asset allocation after market movements cause them to drift. If a 60% equity / 40% debt portfolio earns a strong equity year, equity may drift to 72% — rebalancing sells equity and buys debt to restore the 60/40 split. The academic foundation lies in mean-variance optimization (Markowitz 1952, "Portfolio Selection," Journal of Finance, 7(1), 77–91): the target allocation represents a risk/return optimum on the efficient frontier, and drift moves the portfolio off that optimum. Rebalancing strategies fall into three categories: (a) calendar-based (quarterly, semi-annually, annually), (b) threshold-based (rebalance when any asset class deviates >5% from target), and (c) hybrid (annual review with threshold triggers). Vanguard Research (Jaconetti, Kinniry & Zilbering, 2010, "Best Practices for Portfolio Rebalancing") found threshold-based hybrid rebalancing minimises both tracking error to target allocation and transaction costs relative to pure calendar or pure threshold approaches.
How it manifests in Indian retail investing
Rebalancing is structurally underutilized in Indian retail portfolios for three behavioral reasons: (a) investors confuse rebalancing (a risk-management process) with market timing (a return-prediction process), generating regret aversion about selling an outperforming asset; (b) taxation friction in India makes equity rebalancing taxable — LTCG at 10% beyond ₹1 lakh annual exemption for equity funds — creating a real economic friction not present in, say, US tax-sheltered accounts; (c) the psychological difficulty of selling "winners" (loss aversion and disposition effect). AMFI data shows that the equity-to-debt allocation in Indian retail MF portfolios has drifted from approximately 55:45 in March 2020 to 72:28 in March 2024 — a four-year rebalancing failure across the industry. During this period the portfolio became materially riskier than investors' stated objectives.
What the data shows
Vanguard's 2023 analysis of 2.5 million client portfolios found that portfolios that had not been rebalanced in 5+ years had equity allocations averaging 12 percentage points above target, increasing portfolio standard deviation by approximately 3.2 percentage points annually. In India, the FY2024 AMFI Fact Book shows that balanced/hybrid fund AUM grew only 8% year-on-year in FY2024 despite 40%+ equity market returns — suggesting that investors who would naturally rebalance into hybrid funds were not doing so, letting equity drift. The cost of no-rebalancing is context-dependent: in an uninterrupted bull market it costs nothing; in a correction it converts latent sequence-of-returns risk into realized loss (a ₹10 lakh portfolio drifted to 72% equity loses ₹72,000 in a 10% equity decline versus ₹60,000 at 60% equity — a 20% larger loss).
Worked example
A 40-year-old investor sets a target allocation of 65% equity / 35% debt in April 2020 (post-COVID low). By April 2022, Nifty 50 has doubled: equity portion has grown to 79% of portfolio value (₹7.9 lakh equity / ₹2.1 lakh debt on a ₹10 lakh portfolio). A threshold-based rebalance triggers at 70% (5% drift rule) in January 2021. The rebalance sells ₹1.05 lakh of equity and buys ₹1.05 lakh of debt, restoring 65/35. If no rebalance occurs and Nifty falls 20% in H1 FY2023 (which it did), the unbalanced portfolio loses ₹7.9 lakh × 20% = ₹1.58 lakh. The rebalanced portfolio (65% equity) loses ₹6.5 lakh × 20% = ₹1.30 lakh. The rebalancing saved ₹28,000 in the correction — mechanically selling high and buying low without any market forecast.
How to recognise it in yourself
Rebalancing audit: (1) What is the current equity/debt/gold split versus the target allocation written down at the time of the financial plan? If the deviation exceeds 10 percentage points, a rebalance review is overdue. (2) Has any single equity fund or stock grown to represent >20% of total portfolio value when the original weight was <10%? Concentration drift is a specific rebalancing risk. (3) Is the reason for not rebalancing "the equity is still going up" — a return forecast — rather than an allocation logic? This conflates rebalancing with market timing. (4) For taxable accounts: has the LTCG annual exemption limit (₹1.25 lakh for FY2025 budget) been utilized this year? Rebalancing within the exemption window is the tax-efficient path.
See also
Primary sources
- Markowitz, H. (1952). Portfolio Selection. Journal of Finance, 7(1), 77–91.
- Jaconetti, C.M., Kinniry, F.M. & Zilbering, Y. (2010). Best Practices for Portfolio Rebalancing. Vanguard Research.
- AMFI Fact Book FY2024 — Asset Allocation Trends.
MintByte (ARN-314872 / APMI APRN-01658) is a SEBI-registered MFD and GIFT City wealth management firm. This glossary entry is educational and does not constitute investment advice.