📚 PASS Investment Adviser (Level 1) Difficulty: Intermediate ℹ️ Info   ~5 min read
📌 Chapter 15.14 — Asset allocation decision

Imagine you are reviewing a client’s portfolio that started as a balanced 60/40 mix between Nifty 50 index funds and high-grade corporate bonds. Due to a prolonged equity market rally over the last eighteen months, the equity portion has drifted upward to represent 72% of the total value. While the portfolio value has certainly grown, your internal model signals that the portfolio’s volatility profile has shifted significantly beyond the client’s original risk mandate.

You are now at a crossroad: do you ignore the drift in hopes of further gains, or do you execute a rebalancing trade to restore the target risk parameters?

Monitoring and rebalancing represent the mechanical heart of long-term investment success. Monitoring involves setting predefined triggers—such as calendar-based reviews or percentage-based drift thresholds—to track whether the portfolio aligns with the Investment Policy Statement (IPS). Without this, an investor’s portfolio becomes a victim of its own success, often becoming unintentionally concentrated in the asset class that has performed the best recently. This exposes the portfolio to ‘concentration risk,’ where a sudden market correction in that over-represented sector could disproportionately erode the gains achieved.

Rebalancing is the act of selling a portion of an outperforming asset class and reinvesting the proceeds into an underperforming one. This process is inherently contrarian; it forces the manager to ‘sell high and buy low’ in a disciplined manner, rather than reacting to market sentiment. For example, if Indian equities surge while government securities remain stagnant, rebalancing requires trimming the equity position to buy bonds.

This systematic pruning keeps the portfolio’s risk signature stable, ensuring that the client is not taking on more market exposure than they originally agreed to bear.

Effective rebalancing also requires an awareness of transaction costs and tax implications within the Indian context. Frequent, small-scale rebalancing can lead to ’tax drag’ due to short-term capital gains taxes or high brokerage turnover. Therefore, professionals often utilize ‘corridor rebalancing,’ where trades are triggered only when an asset class deviates by a predetermined percentage, such as ±5% from the target allocation. This balance between strict discipline and cost-efficiency is the hallmark of a high-quality, professional investment process.1

Nuance

⚠️ Nuance
A common pitfall for candidates is the belief that rebalancing is a ‘return-enhancement’ strategy. In truth, rebalancing is a ‘risk-control’ strategy. While it may occasionally capture a mean-reversion premium, its primary purpose is to keep the portfolio’s risk metrics—like Beta or Value at Risk—aligned with the client’s IPS. Analysts who view rebalancing solely as a way to beat the market often abandon the process during strong bull markets, failing to realize that the risk they are ignoring is the very reason the IPS was drafted in the first place.

Check Your Understanding

Practice Question 1

An equity-heavy portfolio has drifted 8% above its target allocation due to a market boom. The investment policy suggests rebalancing when drift exceeds 5%. What should be the primary justification for this rebalancing action?

Practice Question 2

Which of the following describes the ‘corridor rebalancing’ approach in a portfolio management context?

This is a companion read for Section 15.14 — Asset allocation decision from PASS Investment Adviser (Level 1) by Akhilesh Gururani, available on Amazon Kindle.

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  1. Corridor rebalancing minimizes turnover and associated transaction costs by allowing minor fluctuations to persist while acting decisively only when the portfolio drifts into an unacceptable risk zone. ↩︎