AON vs SPY: Correlation
How closely do Aon plc (AON) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.22, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AON and SPY?
Over the past 3 years, AON and SPY moved with a correlation of 0.22, which is weak. Recent behaviour matches the longer record: 0.14 over 1 year against 0.22 over 3. Over 5 years the correlation is 0.42, and the annualized covariance of weekly returns is 70.5 %².
By 3-year correlation, SPY places #20 of the 32 assets tracked against AON. The last year tells two different stories: SPY led by 25.2 percentage points, -4.6% for AON against +20.6% for SPY. The relationship is regime-dependent: the rolling one-year correlation swung between -0.03 and 0.54 over the past three years, so this pair behaves very differently depending on the market environment.
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.
AON vs SPY: side by side
| AON (Aon plc) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -4.6% | +20.6% |
| 5-year return | +27.0% | +82.4% |
| Volatility (ann.) | 21.7% | 14.5% |
| Beta vs S&P 500 | 0.34 | 1.00 |
| Max drawdown (3Y) | -24.2% | -18.8% |
| Market cap | $74.2B | – |
| P/E (trailing) | 19.5 | – |
| Dividend yield | 0.86% | 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 | AON | SPY |
|---|---|---|
| 2022 | +0.6% | -18.2% |
| 2023 | -2.3% | +26.2% |
| 2024 | +24.5% | +24.9% |
| 2025 | -1.2% | +17.7% |
| 2026 | -0.5% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
Keep in mind that SPY holds AON at a 0.11% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are AON and SPY good diversifiers for each other?
Reasonably. At 0.22, AON and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between AON and SPY?
The AON/SPY correlation stands at 0.22 on a 3-year window (1 year: 0.14, 5 years: 0.42), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for AON?
Reasonably. At 0.22, AON and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.22 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.
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Related comparisons
Hubs: AON correlations · SPY correlations
