Pair · Stocks & ETFs
S&P 500 ETF vs Dow Jones ETF
As of 22 Oct 2026, S&P 500 ETF (SPY) and Dow Jones ETF (DIA) have a 120-day daily-return correlation of 0.78 — strong positive. Their prices did not pass the Engle–Granger cointegration test at the 5% level, so their ratio hasn’t shown a stable tether over this window.
Last updated 22 Oct 2026 · data through the 22 Oct 2026 UTC daily candle
The working detail for SPY/DIA
- Hedge ratio and mean-reversion half-life
- Live spread z-score with a ±2σ band — how stretched the pair is today
- Rolling history of the relationship, and the days it breaks down
- Pass/fail gates and a composite score across every tracked pair
Common questions
Are S&P 500 ETF and Dow Jones ETF correlated?
As of 22 Oct 2026, the correlation between SPY and DIA daily returns over the last 120 days is 0.78 (strong positive). Near 1 means they usually move the same way on the same day; near 0, independently; below 0, in opposite directions.
Are SPY and DIA cointegrated?
Not right now. As of 22 Oct 2026, their prices did not pass the Engle–Granger cointegration test at the 5% level over the last 120 days. The test is re-run every day on fresh prices, so the answer can change.
What’s the difference between correlation and cointegration?
Correlation measures whether two assets’ daily returns move together. Cointegration asks something stronger: whether the gap between their prices — their ratio — is tethered and tends to pull back toward its usual level. Two assets can be highly correlated yet drift apart for months; that is correlation without cointegration.