Many mutual fund investors in India believe that owning multiple mutual funds automatically means their portfolio is well-diversified. However, a common pitfall known as mutual fund overlap can quietly expose you to high concentration risk without your knowledge.

In this article, we’ll unpack what mutual fund overlap is, why it occurs, and how you can manage it to build a more resilient investment portfolio.

What is Mutual Fund Overlap?

Mutual fund overlap (or portfolio overlap) occurs when you hold two or more mutual funds that invest in the exact same underlying stocks.

For example, if you own both Fund A and Fund B, and both funds allocate 8% of their assets to Reliance Industries and 6% to HDFC Bank, you have a high level of overlap between those two holdings. Instead of having two independent investments, you are effectively doubling down on the same set of businesses.

Why Does Overlap Happen?

Overlap is especially common in Indian equity markets due to several factors:

  1. Strict SEBI Categorization: SEBI (Securities and Exchange Board of India) has defined clear mandates for fund categories. For instance, Large Cap funds must invest at least 80% of their assets in the top 100 stocks by market capitalization. Since the pool of large-cap stocks is limited, different fund managers naturally select many of the same high-performing stocks.
  2. Index Constraints: Many active managers track popular indices like the Nifty 50 or Nifty LargeMidcap 250 closely to avoid underperforming their benchmarks. This leads to portfolios that closely mirror the index and, consequently, each other.
  3. Popular Market Favorites: Certain high-liquidity, high-growth stocks are staples in almost every diversified equity fund, leading to automatic overlap across multi-cap, large-cap, and flexi-cap categories.

Why Should You Care About Overlap?

While some overlap is normal and inevitable, excessive overlap (typically above 30-40%) poses several risks:

1. Illusion of Diversification

You might feel secure knowing you hold five different funds. But if those funds have 60% overlap, you essentially own one large, expensive, consolidated fund. If those top-heavy sectors or stocks face a downturn, your entire portfolio will take a hit.

2. Double Fees (Expense Ratio)

Every mutual fund charges an annual management fee known as the Expense Ratio. If two funds hold almost identical portfolios, you are paying two different management teams to do the exact same job.

3. Sub-optimal Returns

If you hold multiple active funds with high overlap, their individual active bets can cancel each other out, leading to performance that matches a cheap index fund but with much higher fees.

How Much Overlap is Too Much?

As a general rule of thumb for equity portfolios:

  • 0% to 20% (Low Overlap): Excellent. Your funds are highly complementary and cover different market caps, sectors, or investment styles.
  • 20% to 50% (Moderate Overlap): Common, especially if you hold funds in similar categories (like two Large & Mid Cap funds). This is acceptable, but you should monitor sector weightage.
  • 50% or Higher (High Overlap): Excessive. You should evaluate if you need both funds. Merging them or switching one to a different style (e.g., small-cap, international, or thematic) could improve diversification.

How to Reduce Portfolio Overlap

If you check your portfolio using our Mutual Fund Overlap Tool and discover high overlap, here are steps you can take:

  1. Consolidate Similar Categories: Avoid holding more than one fund in the same SEBI category (e.g., do not hold two Flexi Cap funds or two Mid Cap funds from different AMCs).
  2. Mix Investment Styles: Pair an active fund with a passive index fund, or combine a value-oriented fund with a growth-oriented fund.
  3. Diversify Across Market Capitalizations: Ensure you have clear, distinct allocations to Large Cap, Mid Cap, and Small Cap funds.
  4. Consider International or Gold Funds: Introduce asset classes that have zero correlation to Indian equities.

Conclusion

Diversification is the only free lunch in investing, but true diversification requires looking under the hood at the underlying stock holdings. Regularly monitoring your mutual fund overlap ensures that your portfolio remains balanced, cost-effective, and aligned with your long-term financial goals.