MDY vs XLI: Correlation & Overlap
Measured on weekly returns over the past three years, SPDR S&P MidCap 400 ETF (MDY) and Industrial Select Sector SPDR Fund (XLI) carry a correlation of 0.89, a very strong link. By holdings, the two funds overlap 0% by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and XLI?
Over the past 3 years, MDY and XLI moved with a correlation of 0.89, which is very strong, meaning they move nearly in lockstep. Recent behaviour matches the longer record: 0.81 over 1 year against 0.89 over 3. Over 5 years the correlation is 0.91, and the annualized covariance of weekly returns is 231.3 %².
Among the 359 assets we track against MDY, XLI ranks #9 by 3-year correlation. Their 12-month results are close: +18.3% for MDY against +18.3% for XLI. The rolling one-year correlation stayed in a tight band between 0.79 and 0.94 over the past three years, which points to a structural rather than episodic relationship.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
MDY vs XLI: side by side
| MDY (SPDR S&P MidCap 400 ETF) | XLI (Industrial Select Sector SPDR Fund) | |
|---|---|---|
| 1-year return | +18.3% | +18.3% |
| 5-year return | +47.5% | +84.0% |
| Volatility (ann.) | 16.5% | 15.7% |
| Beta vs S&P 500 | 0.91 | 0.89 |
| Max drawdown (3Y) | -24.0% | -18.5% |
| Dividend yield | 1.02% | 1.15% |
| Expense ratio | 0.23% | 0.08% |
| Assets under management | $26.5B | $32.9B |
| Sector / category | ETF · US Small & Mid Cap | Sector ETF |
On the fund side, MDY sits in the Mid-Cap Blend category at State Street Investment Management, with $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield. XLI is an Industrials fund from State Street Investment Management: $32.9B under management, 83 holdings, a 0.08% expense ratio, a 1.15% trailing dividend yield.
Portfolio overlap between MDY and XLI
The two portfolios are largely distinct, with 0 holdings in common adding up to 0% of fund weight. Where correlation shows the co-movement, the overlap shows its source.
Largest positions held only by MDY: TWLO (0.95%), P (0.94%), ILMN (0.93%), FTI (0.83%), ATI (0.80%). Only by XLI: CAT (6.68%), GE (6.52%), RTX (5.04%), GEV (4.52%), UNP (3.25%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26.
Year-by-year returns
| Year | MDY | XLI |
|---|---|---|
| 2022 | -13.3% | -5.6% |
| 2023 | +16.1% | +18.1% |
| 2024 | +13.6% | +17.3% |
| 2025 | +7.2% | +19.3% |
| 2026 | +16.4% | +15.9% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and XLI good diversifiers for each other?
Not really. At 0.89, the two trade almost as one position, and owning both buys little extra protection.
FAQ
What is the correlation between MDY and XLI?
As of 2026-08-27, the correlation of weekly returns between MDY and XLI is 0.89 over 3 years, 0.81 over 1 year and 0.91 over 5 years.
Is XLI a good diversifier for MDY?
Not really. At 0.89, the two trade almost as one position, and owning both buys little extra protection.
How much do MDY and XLI overlap?
The two funds share 0 holdings amounting to 0% of weight, per issuer portfolio files dated 2026-08-26.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-xli.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/mdy-vs-xli/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: MDY correlations · XLI correlations
