IEX vs SPY: Correlation
IDEX Corporation (IEX) and SPDR S&P 500 ETF Trust (SPY) show a moderate relationship: their 3-year correlation of weekly returns is 0.55.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IEX and SPY?
Over the past 3 years, IEX and SPY moved with a correlation of 0.55, which is moderate. Lately the two have drifted apart, with the 1-year correlation at 0.34 versus 0.55 over 3 years. Over 5 years the correlation is 0.60, and the annualized covariance of weekly returns is 186.7 %².
By 3-year correlation, SPY places #22 of the 40 assets tracked against IEX. The last year tells two different stories: IEX led by 22.4 percentage points, +43.0% for IEX against +20.6% for SPY. On a rolling one-year basis the correlation drifted between 0.33 and 0.70, a moderate band. Risk is not evenly split, since IEX carries 1.6 times the volatility of the other side.
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.
IEX vs SPY: side by side
| IEX (IDEX Corporation) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +43.0% | +20.6% |
| 5-year return | +10.5% | +82.4% |
| Volatility (ann.) | 23.3% | 14.5% |
| Beta vs S&P 500 | 0.89 | 1.00 |
| Max drawdown (3Y) | -34.6% | -18.8% |
| Market cap | $17.2B | – |
| P/E (trailing) | 33.8 | – |
| Dividend yield | 1.23% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | Industrials | 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 | IEX | SPY |
|---|---|---|
| 2022 | -2.2% | -18.2% |
| 2023 | -3.8% | +26.2% |
| 2024 | -2.4% | +24.9% |
| 2025 | -13.7% | +17.7% |
| 2026 | +32.9% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IEX and SPY good diversifiers for each other?
To a limited degree. At 0.55 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between IEX and SPY?
Using weekly returns as of 2026-08-27: 0.55 over 3 years, with 0.34 over the last year and 0.60 over 5 years.
Is SPY a good diversifier for IEX?
To a limited degree. At 0.55 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.55 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: IEX correlations · SPY correlations
