Investment Analysis

ETF Overlap

When multiple ETFs or funds in your portfolio hold the same stocks, creating unintended concentration risk.

Also known as: fund overlap, portfolio overlap

What You Need to Know

ETF overlap occurs when you own multiple index funds or ETFs that hold many of the same stocks, defeating the purpose of diversification. This is common because many funds track similar indices.

Example of Overlap:

  • Fund A: S&P 500 Index (VOO)
  • holds Apple, Microsoft, Amazon
  • Fund B: Total Stock Market (VTI) - 80% overlap with S&P 500
  • Fund C: Tech ETF (VGT) - 40% Apple, Microsoft, Nvidia

If you own all three, you're overweighted in big tech stocks. When tech crashes, your "diversified" portfolio crashes together.

Common Overlap Scenarios:

  1. S&P 500 + Total Market Funds: 80% overlap (redundant)
  2. Growth + Large-Cap Funds: Often 60-70% overlap
  3. Sector ETFs + Broad Index: Double exposure to certain stocks

How to Check: Use an ETF overlap tool to compare holdings. Input ticker symbols (e.g., VOO, VTI, QQQ) and see:

  • Which stocks appear in multiple funds
  • What percentage of holdings overlap
  • Where you're overconcentrated

Solution:

  • Replace overlapping funds with truly complementary ones
  • Use international funds (VXUS) for real diversification
  • Consider bond funds (BND) for asset class diversification
  • Simplify: Often one total market fund is enough

Goal: True diversification means when one sector crashes, others cushion the blow. Overlap destroys this protection.

Sources & References

This information is sourced from authoritative government and academic institutions:

  • sec.gov

    https://www.sec.gov/files/ib_etfs.pdf