SAIA vs SPY: Correlation
Measured on weekly returns over the past three years, Saia, Inc. (SAIA) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.36, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SAIA and SPY?
Over the past 3 years, SAIA and SPY moved with a correlation of 0.36, which is moderate. Recent behaviour matches the longer record: 0.30 over 1 year against 0.36 over 3. Over 5 years the correlation is 0.45, and the annualized covariance of weekly returns is 260.2 %².
Among the 12 assets we track against SAIA, SPY ranks #6 by 3-year correlation. Their 12-month results are close: +16.6% for SAIA against +20.6% for SPY. One caveat on sizing: SAIA is 3.5 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.
SAIA vs SPY: side by side
| SAIA (Saia, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +16.6% | +20.6% |
| 5-year return | +44.1% | +82.4% |
| Volatility (ann.) | 50.1% | 14.5% |
| Beta vs S&P 500 | 1.25 | 1.00 |
| Max drawdown (3Y) | -60.9% | -18.8% |
| Market cap | $9.4B | – |
| P/E (trailing) | 33.8 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | 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 | SAIA | SPY |
|---|---|---|
| 2022 | -37.8% | -18.2% |
| 2023 | +109.0% | +26.2% |
| 2024 | +4.0% | +24.9% |
| 2025 | -28.4% | +17.7% |
| 2026 | +8.1% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SAIA and SPY good diversifiers for each other?
Reasonably. At 0.36, SAIA and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between SAIA and SPY?
The SAIA/SPY correlation stands at 0.36 on a 3-year window (1 year: 0.30, 5 years: 0.45), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for SAIA?
Reasonably. At 0.36, SAIA and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.36 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: SAIA correlations · SPY correlations
