AJG vs SPY: Correlation
Measured on weekly returns over the past three years, Arthur J. Gallagher & Co. (AJG) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.21, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AJG and SPY?
Across a 3-year window, the weekly returns of AJG and SPY correlate at 0.21, weak. The past 12 months show a weaker link (0.08) than the 3-year average (0.21). Stretching to 5 years gives 0.41, with an annualized covariance of 76.0 %².
Among the 32 assets we track against AJG, SPY ranks #19 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 32.5 percentage points (-11.9% for AJG against +20.6% for SPY). The relationship is regime-dependent: the rolling one-year correlation swung between 0.03 and 0.56 over the past three years, so this pair behaves very differently depending on the market environment. Note the risk asymmetry: AJG runs 1.7 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.
AJG vs SPY: side by side
| AJG (Arthur J. Gallagher & Co.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -11.9% | +20.6% |
| 5-year return | +91.1% | +82.4% |
| Volatility (ann.) | 25.0% | 14.5% |
| Beta vs S&P 500 | 0.36 | 1.00 |
| Max drawdown (3Y) | -44.4% | -18.8% |
| Market cap | $66.7B | – |
| P/E (trailing) | 43.1 | – |
| Dividend yield | 1.02% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | Financials | ETF · US Large Cap |
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 | AJG | SPY |
|---|---|---|
| 2022 | +12.4% | -18.2% |
| 2023 | +20.5% | +26.2% |
| 2024 | +27.3% | +24.9% |
| 2025 | -8.0% | +17.7% |
| 2026 | +1.2% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.1% of SPY is AJG itself, so the fund partly moves with the stock by construction.
Are AJG and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.21 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between AJG and SPY?
The AJG/SPY correlation stands at 0.21 on a 3-year window (1 year: 0.08, 5 years: 0.41), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for AJG?
Yes, to a useful degree: a correlation of 0.21 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.21 mean?
A reading of 0.21 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: AJG correlations · SPY correlations
