Dow Jones Industrial Average Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
10.99%
increased by 0.08%
1 Week
11.40%
increased by 0.49%
1 Month
12.64%
increased by 1.73%
Analysis last updated: Tuesday, July 21, 2026 at 12:03 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Jul 17, 2026Model Insight
This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 21 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.4464 | 6.99*** |
α ARCH Response to squared shocks | 0.1024 | 9.70*** |
β GARCH Volatility persistence | 0.8656 | 73.10*** |
Spline Coefficients
K=6
| γ1 | 0.0722 | 5.56*** |
| γ2 | -0.1128 | -5.40*** |
| γ3 | 0.0613 | 4.00*** |
| γ4 | -0.0337 | -2.48** |
| γ5 | 0.0282 | 1.91* |
| γ6 | -0.0226 | -2.03** |
Persistence:
0.968
Half-life:
21 days
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