EXR vs PDEX: Correlation
Measured on weekly returns over the past three years, Extra Space Storage (EXR) and Pro-Dex, Inc. (PDEX) carry a correlation of -0.24, a negative link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are EXR and PDEX?
On 3 years of weekly data the EXR/PDEX correlation comes out at -0.24, negative, meaning they tend to move in opposite directions. Recent behaviour matches the longer record: -0.23 over 1 year against -0.24 over 3. The 5-year figure is -0.13, and annualized covariance runs at -364.0 %².
PDEX is close to the least connected end of EXR's tracked universe, ranking #31 of 33. Their recent paths diverged sharply: over the last 12 months PDEX outperformed by 36.9 percentage points (+5.6% for EXR against +42.5% for PDEX). Note the risk asymmetry: PDEX runs 2.3 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.
EXR vs PDEX: side by side
| EXR (Extra Space Storage) | PDEX (Pro-Dex, Inc.) | |
|---|---|---|
| 1-year return | +5.6% | +42.5% |
| 5-year return | -6.1% | +152.4% |
| Volatility (ann.) | 26.0% | 59.6% |
| Beta vs S&P 500 | 0.68 | 0.17 |
| Max drawdown (3Y) | -29.4% | -65.3% |
| Market cap | $31.5B | $0.2B |
| P/E (trailing) | 31.6 | 17.5 |
| Dividend yield | 4.50% | 0.00% |
| Sector / category | Real Estate | US Listed |
Year-by-year returns
| Year | EXR | PDEX |
|---|---|---|
| 2022 | -32.8% | -31.5% |
| 2023 | +13.9% | +10.2% |
| 2024 | -2.8% | +166.8% |
| 2025 | -8.9% | -17.7% |
| 2026 | +12.1% | +68.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are EXR and PDEX good diversifiers for each other?
By historical standards, yes. A correlation of -0.24 means the two rarely move for the same reasons.
FAQ
What is the correlation between EXR and PDEX?
Using weekly returns as of 2026-08-27: -0.24 over 3 years, with -0.23 over the last year and -0.13 over 5 years.
Is PDEX a good diversifier for EXR?
By historical standards, yes. A correlation of -0.24 means the two rarely move for the same reasons.
What does a correlation of -0.24 mean?
On the −1 to +1 scale, -0.24 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/exr-vs-pdex.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/exr-vs-pdex/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: EXR correlations · PDEX correlations
