Does it diversify me?
The large US ETFs with the lowest weekly correlation with yours, one per group, or the overlap and correlation of the ETFs you choose.
Examples
Weekly correlation over the 156 weeks to 2026-10-12. One click opens the whole answer at its own address, every ETF of the list measured.
Examples to compare
One click opens the answer at its own address, with the form filled in.
How these are measured
- Overlap
- The sum, over the companies both hold, of the smaller of two weights: the company's weight in the candidate, and its weight in the portfolio, which is its weight in each of the portfolio's ETFs times that ETF's weight. An ETF that holds no shares adds nothing to the portfolio's side. For an ETF read from its SEC filings, a holding the filing lists on a market abroad matches only the same holding abroad.
- Share in companies held
- The part of the candidate's weight in companies the portfolio also holds, each counted at the candidate's own weight. It is never below the overlap, which counts the smaller of the two weights.
- Weekly correlation
- Pearson's correlation between the candidate's weekly returns and the portfolio's, on the weeks both have: at most the 156 the files carry, at least 52. The portfolio's weekly return is the return of its ETFs at their weights, counting every ETF with at least 52 weekly returns here, whatever it holds. A weekly return is a weekly total return, from the last close of one week to the last close of the next, with dividends reinvested, as in the fund files. The weeks end on Fridays, or on the Thursday when the exchange is shut that Friday, and the last one ends on the files' last close.
- On down weeks
- The same correlation on the weeks the portfolio's return was below zero, when there are at least 20.
- Mega-cap tech
- A fixed list, the one every fund file's breakdown and every ETF page count: Apple, Microsoft, Nvidia, Alphabet, Amazon, Meta Platforms, Broadcom and Tesla, every listed class of each.
- Sectors
- Each ETF's breakdown, as its fund file and ETF page give it. A company's sector is the one most of the single-sector index funds that hold it belong to, each fund one vote, or else the sector of its SEC industry code. When a sector is found for under 50% of an ETF's stock weight, no sector weight is given. A portfolio's breakdown is its ETFs' at their weights.
- Countries
- Each ETF's breakdown, as its fund file gives it. A line listed abroad counts under the country of its market. A US-listed line counts under the United States, unless its company files with the SEC as a foreign issuer or is Canadian: it then counts under the country of the company's business address. A fund held by a fund counts under the United States.
- Order
- By overlap, lowest first, then by weekly correlation, lowest first, each as printed (one and two decimals). An ETF with a figure not measured comes after those measured, then in the order asked.
- Volatility
- The standard deviation of the weekly returns over the weeks counted, times the square root of 52, in percent, as each ETF page gives it over 156 weeks.
- With 10% in each
- The same volatility for the portfolio with 10% in one ETF of the list and 90% in the ETFs held with a price history here, at their weights among them, rebalanced to those weights every week, over the weeks the two have in common. The 10% is the same for every ETF and every portfolio.
- Order of the lowest correlation with yours
- From the ETFs of the list, leaving out any ETF the portfolio holds: in each group, the ETF whose weekly returns had the lowest correlation with the portfolio's over the weeks both have, up to 156, compared before rounding; the answer opens on the 3 groups whose lowest is lowest, and an exact tie keeps the order of the list.
The same answer for programs: the diversify endpoint of the JSON API, and the does_this_etf_diversify_my_portfolio prompt of the MCP server.
The 30 ETFs and the rule
From the ETFs of the list, leaving out any ETF the portfolio holds: in each group, the ETF whose weekly returns had the lowest correlation with the portfolio's over the weeks both have, up to 156, compared before rounding; the answer opens on the 3 groups whose lowest is lowest, and an exact tie keeps the order of the list.
- US stocks
- VTI, RSP, QQQ, VTV, SCHD, VO, IWM, AVUV, USMV, QUAL, MTUM
- Sector stocks
- XLU, XLP, XLV, XLE, VNQ, VNQI, IGF
- International stocks
- VXUS, VEA, AVDV
- Emerging market stocks
- VWO
- Bonds
- BND, SHY, IEF, TLT, TIP, LQD, HYG
- Commodities
- GLD
Chosen on 2026-10-10: 30 large US ETFs across six kinds of exposure, one ETF per exposure, the same list for every portfolio. Left out on purpose: S&P 500 ETFs weighted by company size, near duplicates of VTI; sector ETFs for technology, financials, industrials, consumer discretionary, communication services and materials; Treasury bills; single commodities other than gold; gold miners; bitcoin; and leveraged, inverse and volatility products. The list and its weekly returns as one file: candidates.json.
