What Is Portfolio Rebalancing? Keeping Your Allocation on Track

Portfolio rebalancing is the process of periodically adjusting a portfolio's holdings back to a predetermined target asset allocation, addressing the natural drift that occurs as different assets grow or decline at different rates over time.

Why Portfolios Naturally Drift From Their Target Allocation

An investor might start with a target allocation of 70% equities and 30% debt instruments. If equities significantly outperform debt over the following year, the portfolio's actual allocation might shift to, say, 78% equities and 22% debt, simply due to the equities portion growing faster in value — without the investor making any new deliberate decisions, their risk profile has effectively shifted toward being more aggressive than originally intended.

How Rebalancing Restores the Target Allocation

Rebalancing involves selling a portion of the now-overweight asset class (equities, in the example above) and reallocating those proceeds into the now-underweight asset class (debt), bringing the portfolio back toward its original 70/30 target. This process essentially enforces a disciplined "sell high, buy low" approach — trimming an asset class that has performed well and grown to a larger share, while adding to an asset class that has lagged and now represents a smaller share.

Common Rebalancing Approaches

Time-based rebalancing involves reviewing and adjusting the portfolio at set intervals — commonly annually or semi-annually — regardless of how much drift has actually occurred by that point. Threshold-based rebalancing involves rebalancing whenever an asset class's actual allocation drifts beyond a predetermined percentage from its target — for example, rebalancing whenever equities exceed 75% or fall below 65% of the target 70% allocation, rather than on a fixed calendar schedule.

Why Rebalancing Matters for Risk Management

Without periodic rebalancing, a portfolio's risk profile can gradually shift significantly from what an investor originally intended, often becoming more aggressive during strong bull markets (as equities grow to represent a larger share) — precisely the point at which taking on additional, unintended risk could be most costly if a subsequent downturn occurs. Rebalancing helps maintain a risk level that remains aligned with an investor's actual risk tolerance and goals over time.

FAQ

Does rebalancing have tax implications? Yes, selling appreciated assets as part of rebalancing can trigger capital gains tax, which is worth factoring into the rebalancing decision and timing, particularly for taxable investment accounts.

How often should a typical investor rebalance their portfolio? There's no single correct frequency, but many financial advisors suggest reviewing and potentially rebalancing annually or semi-annually as a reasonable, manageable starting point for most individual investors.

Portfolio rebalancing maintains discipline around an investor's intended asset allocation and risk level, counteracting the natural drift that occurs as different asset classes perform differently over time. This is general information, not personalized investment advice.

Sources

• Securities and Exchange Board of India — sebi.gov.in
• Association of Mutual Funds in India — amfiindia.com