SPY vs WLDN: Correlation
How closely do SPDR S&P 500 ETF Trust (SPY) and Willdan Group, Inc. (WLDN) trade together? Their weekly returns over three years give a correlation of 0.27, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and WLDN?
On 3 years of weekly data the SPY/WLDN correlation comes out at 0.27, weak. Little has changed lately, as the 1-year reading of 0.28 lands near the 3-year figure. The 5-year figure is 0.32, and annualized covariance runs at 204.8 %².
By 3-year correlation, WLDN places #2589 of the 4755 assets tracked against SPY. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 45.0 percentage points (+20.6% for SPY against -24.4% for WLDN). One caveat on sizing: WLDN is 3.6 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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.
SPY vs WLDN: side by side
| SPY (SPDR S&P 500 ETF Trust) | WLDN (Willdan Group, Inc.) | |
|---|---|---|
| 1-year return | +20.6% | -24.4% |
| 5-year return | +82.4% | +134.3% |
| Volatility (ann.) | 14.5% | 52.6% |
| Beta vs S&P 500 | 1.00 | 0.98 |
| Max drawdown (3Y) | -18.8% | -50.4% |
| Market cap | – | $1.3B |
| P/E (trailing) | – | 20.2 |
| Dividend yield | 1.01% | 0.00% |
| Expense ratio | 0.09% | – |
| Assets under management | $795.3B | – |
| Sector / category | ETF · US Large Cap | US Listed |
SPY is a Large Blend fund from State Street Investment Management: $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | SPY | WLDN |
|---|---|---|
| 2022 | -18.2% | -49.3% |
| 2023 | +26.2% | +20.4% |
| 2024 | +24.9% | +77.2% |
| 2025 | +17.7% | +172.1% |
| 2026 | +13.7% | -15.2% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and WLDN good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.27 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between SPY and WLDN?
Using weekly returns as of 2026-08-27: 0.27 over 3 years, with 0.28 over the last year and 0.32 over 5 years.
Is WLDN a good diversifier for SPY?
Yes, to a useful degree: a correlation of 0.27 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.27 mean?
A reading of 0.27 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/spy-vs-wldn.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/spy-vs-wldn/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: SPY correlations · WLDN correlations
