J vs MDY: Correlation
Jacobs Solutions (J) and SPDR S&P MidCap 400 ETF (MDY) show a moderate relationship: their 3-year correlation of weekly returns is 0.50.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are J and MDY?
On 3 years of weekly data the J/MDY correlation comes out at 0.50, moderate. The relationship has been stable: the 1-year correlation (0.44) sits close to the 3-year figure. The 5-year figure is 0.58, and annualized covariance runs at 210.3 %².
Within J's tracked universe of 34 assets, MDY comes in at #6 by 3-year correlation. Correlation aside, the last 12 months split them widely, with MDY ahead by 15.7 points (+2.6% versus +18.3%). Across three years, the rolling one-year figure varied moderately, from 0.30 to 0.74. Note the risk asymmetry: J runs 1.6 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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.
J vs MDY: side by side
| J (Jacobs Solutions) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +2.6% | +18.3% |
| 5-year return | +40.5% | +47.5% |
| Volatility (ann.) | 25.7% | 16.5% |
| Beta vs S&P 500 | 0.77 | 0.91 |
| Max drawdown (3Y) | -34.4% | -24.0% |
| Market cap | $17.6B | – |
| P/E (trailing) | 49.9 | – |
| Dividend yield | 0.90% | 1.02% |
| Expense ratio | – | 0.23% |
| Assets under management | – | $26.5B |
| Sector / category | Industrials | ETF · US Small & Mid Cap |
MDY, State Street Investment Management's Mid-Cap Blend fund, carries $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | J | MDY |
|---|---|---|
| 2022 | -13.1% | -13.3% |
| 2023 | +9.0% | +16.1% |
| 2024 | +24.2% | +13.6% |
| 2025 | +1.1% | +7.2% |
| 2026 | +14.6% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are J and MDY good diversifiers for each other?
Somewhat, no more. With 0.50 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between J and MDY?
Using weekly returns as of 2026-08-27: 0.50 over 3 years, with 0.44 over the last year and 0.58 over 5 years.
Is MDY a good diversifier for J?
Somewhat, no more. With 0.50 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.50 mean?
A reading of 0.50 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/j-vs-mdy.json
Embed this badge (it refreshes with the data), with attribution:
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Related comparisons
Hubs: J correlations · MDY correlations
