Owning several ETFs can look diversified on an account screen. Yet if those funds hold many of the same companies, the underlying exposures can be much more concentrated than the number of fund names suggests.
Look through the fund wrapper
Investor.gov explains that a narrowly focused fund, including one devoted to a single industry sector, does not necessarily provide broad diversification. It also recommends checking top holdings across multiple funds to see whether the investments are actually different.
A hypothetical overlap calculation
Imagine a $10,000 portfolio split equally between Fund A and Fund B. Company X represents 12% of A and 8% of B. The exposure through A is $5,000 × 12% = $600. Through B, it is $5,000 × 8% = $400.
Total exposure to X is therefore $1,000, or 10% of the portfolio. Buying two funds did not create two independent positions in unrelated businesses. It created two routes to ownership of the same company.
Now add a separate $1,000 direct holding of X without selling anything else. The portfolio totals $11,000, and exposure to X becomes $2,000, or approximately 18.18%. These are illustrative weights and do not describe real funds.
Map the whole portfolio consistently
A useful worksheet lists each company in rows and each fund in columns. Multiply the portfolio allocation to each fund by that company’s weight inside it. Add any direct shares in a separate column, then sum the row.
Record the holdings date. Combining one fund’s current disclosure with another fund’s old holdings can create a misleading picture of the same-day portfolio.
Overlap is a measurement, not automatically a mistake
An investor may intentionally want more exposure to a business or industry. The analytical problem is assuming that the portfolio is broadly spread simply because it contains several tickers. Measuring the position makes that choice visible.
Questions for a sector fund review
- Which companies appear in more than one holding?
- What is the combined weight of the largest company?
- How much of the portfolio depends on one sector?
- Does a broad-market fund already hold the same businesses?
- Are the weights drawn from comparable disclosure dates?
Start with the underlying holdings, then interpret the fund labels. That order provides a clearer account of what the portfolio actually owns.
Source
SEC Investor.gov: Asset Allocation and Diversification.
Featured image: lonely blue / Unsplash.
