When two or more mutual funds hold the same shares, the portfolio overlap phenomenon emerges. For the average Indian investor, this means that the diversification promised by a diversified equity fund may be less than expected, especially when the funds track the Nifty 50 or Sensex‑linked indices in the current market. Overlap squeezes the benefit of spreading risk across sectors and companies. If several funds in your portfolio are long the same banking or IT stocks, a single market shock can hit multiple holdings simultaneously, eroding the cushion that diversification is supposed to provide.
Detecting overlap is easier than it sounds. Start with the fund’s fact sheet and look for common holdings and sector weights. Many platforms now offer portfolio‑overlap calculators that compare the top 20 holdings of two funds side by side, flagging duplicate names and sector concentration. For retail investors, the takeaway is to review the composition of all mutual funds in your portfolio, especially those that claim to be broad‑based or index‑tracking.
If you find significant overlap, consider swapping one fund for a niche or sector‑specific alternative, or simply rebalance to reduce duplicate exposure. A cleaner mix can protect you from a single‑sector crash and help maintain the expected risk‑return profile.