SPY vs WPRT: Correlation
Measured on weekly returns over the past three years, SPDR S&P 500 ETF Trust (SPY) and Westport Fuel Systems Inc (WPRT) carry a correlation of 0.40, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and WPRT?
Across a 3-year window, the weekly returns of SPY and WPRT correlate at 0.40, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.20 versus 0.40 over 3 years. Stretching to 5 years gives 0.41, with an annualized covariance of 300.3 %².
By 3-year correlation, WPRT places #1194 of the 4755 assets tracked against SPY. The last year tells two different stories: SPY led by 56.1 percentage points, +20.6% for SPY against -35.5% for WPRT. One caveat on sizing: WPRT 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 WPRT: side by side
| SPY (SPDR S&P 500 ETF Trust) | WPRT (Westport Fuel Systems Inc) | |
|---|---|---|
| 1-year return | +20.6% | -35.5% |
| 5-year return | +82.4% | -95.2% |
| Volatility (ann.) | 14.5% | 51.7% |
| Beta vs S&P 500 | 1.00 | 1.44 |
| Max drawdown (3Y) | -18.8% | -80.0% |
| Market cap | – | – |
| P/E (trailing) | – | – |
| Dividend yield | 1.01% | 0.00% |
| Expense ratio | 0.09% | – |
| Assets under management | $795.3B | – |
| Sector / category | ETF · US Large Cap | US Listed |
On the fund side, SPY sits in the Large Blend category at State Street Investment Management, with $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | SPY | WPRT |
|---|---|---|
| 2022 | -18.2% | -67.5% |
| 2023 | +26.2% | -14.0% |
| 2024 | +24.9% | -45.9% |
| 2025 | +17.7% | -56.1% |
| 2026 | +13.7% | +17.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and WPRT good diversifiers for each other?
A fair diversifier. At 0.40, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between SPY and WPRT?
The SPY/WPRT correlation stands at 0.40 on a 3-year window (1 year: 0.20, 5 years: 0.41), computed from weekly returns as of 2026-08-27.
Is WPRT a good diversifier for SPY?
A fair diversifier. At 0.40, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.40 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/spy-vs-wprt.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/spy-vs-wprt/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: SPY correlations · WPRT correlations
