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Correlation Deep Dive

S&P 500 vs 10Y Treasury Yield: Correlation Analysis

Pearson correlation of daily returns for S&P 500 ETF (SPY) and 10Y Treasury Yield. Rolling windows, yearly breakdown, regression beta, and divergence analysis. Data window spans to (1,243 aligned observations).

30-Day
-0.573
Moderate negative
90-Day
-0.275
Weak negative
1-Year
-0.068
Essentially uncorrelated
5-Year
-0.014
Essentially uncorrelated

What the Number Means

A correlation of -0.27 signals only a weak tendency to move in opposite directions. On most days the two move independently. Do not expect one to reliably predict the other. Look for conditional relationships within specific regimes or event windows.

Recent vs Long-Run Behavior

Last 90 Days
-0.275
5-Year Baseline
-0.014

The correlation has weakened materially. The 90-day reading of -0.27 sits 0.26 below the long-run average of -0.01. Falling correlation signals the dispersion regime where idiosyncratic stories dominate and cross-asset diversification benefits improve.

Statistical Details (1-Year Window)

Pearson Correlation (r)-0.068
R-Squared (r²)0.005
Beta (S&P 500 ETF (SPY) vs 10Y Treasury Yield)-0.054
Daily Volatility σ(S&P 500 ETF (SPY))0.80%
Daily Volatility σ(10Y Treasury Yield)1.00%
Observations252

Correlation measures directional co-movement; R² quantifies the fraction of variance explained by the linear relationship. Beta is the slope coefficient from regressing S&P 500 ETF (SPY) returns on 10Y Treasury Yield returns. A beta above 1 means the first asset amplifies moves of the second.

Year-by-Year Correlation

YearCorrelationStrengthObservations
2026-0.275Weak negative81
2025+0.134Essentially uncorrelated248
2024-0.058Essentially uncorrelated250
2023-0.039Essentially uncorrelated249
2022-0.118Essentially uncorrelated249
2021+0.264Weak positive166

Year-by-year correlation reveals how the relationship has held up across different macro regimes. Sharp year-over-year swings in correlation often mark the transition between stress and calm periods.

Rolling 90-Day Extremes

Most Correlated Period
+0.369
ending 2023-07-11
Most Decoupled Period
-0.433
ending 2022-12-05

Extremes in rolling 90-day correlation often coincide with regime changes, forced deleveraging, or the arrival of a dominant new macro theme that overwhelms normal relationships.

Methodology

Correlations are computed on daily log-adjacent returns for S&P 500 ETF (SPY) and 10Y Treasury Yield, aligned on shared trading dates. We use the Pearson product-moment coefficient, which measures the linear relationship between two return series.

Windows are the most recent N observations for 30D, 90D, and 1Y (252 trading days); the 5Y figure uses all aligned data up to 1,260 observations. Beta is the OLS slope from regressing the first series on the second. Data updates daily with a 24-hour revalidation cadence.

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Get daily macro analysis on shifting correlations, regime transitions, and cross-asset signals.

Correlation is not causation and backward-looking statistics can fail when regimes shift. Positions sized on historical correlation assumptions should be stress-tested against scenarios where the relationship breaks. For informational purposes only.