Portfolio Rebalancing Calculator

Why Portfolios Drift and Why It Matters

You set your target allocation at 60% equity, 30% debt, 10% gold. One year of strong equity markets later, equity has grown to 72% of your portfolio. Debt and gold are now underweight. Your risk profile has shifted — not because you made a deliberate decision, but because prices moved.

This drift is the rebalancing problem. Left unchecked, portfolios in a prolonged bull market become increasingly equity-heavy. When the correction comes, the larger-than-intended equity exposure amplifies losses. Rebalancing forces you to trim winners and add to laggards — which is psychologically uncomfortable but mathematically sound.

Calendar vs Threshold Rebalancing

Two main approaches exist. Calendar rebalancing means you rebalance on a fixed schedule — annually is most common, quarterly is more active, monthly is unnecessary for most investors. Threshold rebalancing means you rebalance whenever any asset class drifts more than a fixed percentage — typically 5% — from its target.

Research suggests threshold rebalancing (5% band) slightly outperforms annual calendar rebalancing in terms of risk-adjusted returns, because it captures larger dislocations. But it requires more active monitoring and generates more transactions. For most Indian retail investors, annual calendar rebalancing on a fixed date (say, April 1 each year, after financial year close) is the right balance of effort and effectiveness.

Tax Implications of Rebalancing in India

Rebalancing by selling appreciated assets triggers capital gains tax. Selling equity held less than 12 months incurs 20% STCG. Equity held more than 12 months incurs 12.5% LTCG on gains above ₹1.25 lakh. Debt fund redemptions are taxed at slab rates regardless of holding period (post April 2023 rule change).

One tax-efficient rebalancing strategy: use new contributions to rebalance rather than selling existing positions. If equity is overweight, direct all new SIP investments to debt for a period until balance is restored. This works well during accumulation phase when you're adding money regularly.

Another approach: rebalance within tax-exempt accounts first. Contributions to EPF and NPS don't create rebalancing tax events. If you're making voluntary NPS contributions, you can adjust between equity and debt within NPS without capital gains consequences.

Tax harvesting combined with rebalancing can offset some tax costs. In the same transaction where you sell equity to rebalance, you can also harvest tax losses from underperforming positions to set off against the gains.

Behavioral Benefits of Rebalancing

Beyond the math, rebalancing counteracts two of the most destructive investment behaviors: momentum chasing and panic selling.

Momentum chasing means buying more of what has recently gone up. Threshold rebalancing forces the opposite — trimming what has risen most. It's a value discipline applied at the asset class level, built into the rules.

Panic selling means dumping equity in a crash. A rebalancing framework tells you precisely the opposite — when equity falls and drops below target allocation, you buy more to rebalance back up. This is buying the dip with a rule, not with emotion. Investors who followed rebalancing rules in March 2020 were buying equity when everyone else was selling, and their portfolios recovered faster.