Portfolio Rebalancing: What, Why, and How Often Should You Do It?

In one of our earlier posts, we recommended reviewing your portfolio every 6 months. But what are you supposed to be doing during that review?

And in our last blog, we discussed “Asset Allocation” and finding your perfect mix—say, 70% in Equity and 30% in Debt.

This is where it all comes together. Let’s imagine you set that 70/30 mix a year ago. After a great year, you check your portfolio and see that your equity funds have boomed, while your debt funds have grown slowly.

Now, your portfolio isn’t 70/30 anymore. It has “drifted” to be 80% Equity and 20% Debt.

Without realizing it, you are now taking on far more risk than you originally planned. Portfolio Rebalancing is the simple, disciplined process of “course correction” to get your portfolio back on track.

What is Portfolio Rebalancing?

Rebalancing is the act of periodically buying or selling assets in your portfolio to get back to your original, target asset allocation.

Think of it this way: your asset allocation is your financial “game plan.” But as the market moves, your players get out of position. Rebalancing is just calling a timeout and telling your players to get back to their original formations.

It’s the simple act of selling some of your winners (which have grown) and using that money to buy more of your laggards (which have shrunk or stayed flat).

Why is This So Important?

This might sound simple, but it’s one of the most powerful (and most skipped) steps in investing.

1. It Manages Your Risk (The Main Goal) This is the #1 reason to rebalance. A portfolio that drifts from 70% to 80% equity is not the portfolio you designed. It’s a much more aggressive, high-risk portfolio. When the next market crash happens, an 80% equity portfolio will fall significantly harder and faster, causing you to panic. Rebalancing is your built-in safety check; it locks in your risk level and ensures you’re never taking on more risk than you’re comfortable with.

2. It Forces a “Buy Low, Sell High” Discipline This is the hidden magic of rebalancing. Think about the action it forces you to take:

Your equities have done extremely well (they are “high”).
Your debt funds have underperformed (they are “low”).
To get back to 70/30, you must sell some of your high-flying equities (Selling High).
You must then use that cash to buy more of your underperforming debt funds (Buying Low).

Rebalancing automatically and systematically forces you to do the one thing every investor knows they should do but is too emotional to execute. It removes greed and fear from the equation.

How to Rebalance: A Simple 3-Step Example

Let’s walk through the math.

Step 1: Your Original Plan (Target Allocation)
- Your Target: 70% Equity, 30% Debt
- Your Investment: ₹1,00,000
- (You have ₹70,000 in Equity and ₹30,000 in Debt)
Step 2: One Year Passes (Portfolio Drift)
- Your equity funds had a great year! They grew 20% and are now worth ₹84,000.
- Your debt funds had a slow year, growing 5%. They are now worth ₹31,500.
- Your New Portfolio Value: ₹84,000 + ₹31,500 = ₹1,15,500
- Your New Allocation: Your equity is now 72.7% (84k/115.5k) of your portfolio. You are “overweight” in equity.
Step 3: The Rebalancing Act
- You need to get back to 70/30.
- New 70% Equity Target: 70% of ₹1,15,500 = ₹80,850
- New 30% Debt Target: 30% of ₹1,15,500 = ₹34,650
- The Action: You need to sell ₹3,150 of your equity (₹84,000 – ₹80,850) and use that money to buy ₹3,150 of debt (which brings your ₹31,500 up to the ₹34,650 target).

Result: You are now perfectly back at your 70/30 split. You have locked in some of your equity gains and are ready for the next year.

How Often Should You Rebalance?

As we mentioned in our “Review Your Portfolio” tip, checking in every 6 or 12 months is perfect. There are two main ways to do it:

Time-Based (The Easiest): This is our recommendation for most investors. Pick a date—like your birthday, the financial new year (April 1st), or the new year (Jan 1st)—and rebalance on that day, every single year. It’s simple, easy to remember, and highly effective.
Threshold-Based (More Advanced): Instead of a date, you set a “drift limit.” For example, “I will only rebalance if any asset class moves 5% away from its target.” In this case, your 70% equity would have to hit 75% or 65% before you would act. This requires more monitoring but can be slightly more efficient.

Conclusion:

Rebalancing can feel wrong. It’s hard to sell your best-performing assets. But investing isn’t about endlessly chasing your winners—it’s about managing risk to reach your long-term goals.

Your asset allocation is your map, and rebalancing is the act of checking the map to make sure you’re still on the right road. It’s the single best way to ensure that a short-term market crash doesn’t derail your long-term financial journey.