ACGL vs BLDP: Correlation
How closely do Arch Capital Group (ACGL) and Ballard Power Systems, Inc. (BLDP) trade together? Their weekly returns over three years give a correlation of -0.22, which is negative.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ACGL and BLDP?
Across a 3-year window, the weekly returns of ACGL and BLDP correlate at -0.22, negative, meaning they tend to move in opposite directions. The past 12 months show a weaker link (-0.40) than the 3-year average (-0.22). Stretching to 5 years gives -0.07, with an annualized covariance of -307.4 %².
Within ACGL's tracked universe of 36 assets, BLDP comes in at #28 by 3-year correlation. On 12-month performance BLDP holds a 8.1-point edge, +7.7% against +15.8%. One caveat on sizing: BLDP is 3.1 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.
ACGL vs BLDP: side by side
| ACGL (Arch Capital Group) | BLDP (Ballard Power Systems, Inc.) | |
|---|---|---|
| 1-year return | +7.7% | +15.8% |
| 5-year return | +151.8% | -85.8% |
| Volatility (ann.) | 21.5% | 66.3% |
| Beta vs S&P 500 | 0.28 | 1.62 |
| Max drawdown (3Y) | -22.4% | -76.4% |
| Market cap | $33.7B | $0.7B |
| P/E (trailing) | 7.9 | – |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | Financials | US Listed |
Year-by-year returns
| Year | ACGL | BLDP |
|---|---|---|
| 2022 | +41.2% | -61.9% |
| 2023 | +18.3% | -22.8% |
| 2024 | +30.8% | -55.1% |
| 2025 | +3.9% | +53.0% |
| 2026 | +3.0% | -7.9% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ACGL and BLDP good diversifiers for each other?
Yes: at -0.22, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between ACGL and BLDP?
The ACGL/BLDP correlation stands at -0.22 on a 3-year window (1 year: -0.40, 5 years: -0.07), computed from weekly returns as of 2026-08-27.
Is BLDP a good diversifier for ACGL?
Yes: at -0.22, the two have gone their own ways historically, which is what genuine diversification looks like.
What does a correlation of -0.22 mean?
A reading of -0.22 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
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Related comparisons
Hubs: ACGL correlations · BLDP correlations
