V-Lab
NASDAQ Composite Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, July 31st, 2026
1 Day
23.35%
increased by 3.58%
1 Week
23.27%
increased by 3.50%
1 Month
23.03%
increased by 3.26%
Analysis last updated: Friday, July 31, 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 24, 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 18 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.7547 | 7.40*** |
α ARCH Response to squared shocks | 0.1000 | 10.31*** |
β GARCH Volatility persistence | 0.8630 | 71.76*** |
Spline Coefficients
K=8
| γ1 | 0.0090 | 0.31 |
| γ2 | 0.0499 | 1.12 |
| γ3 | -0.1762 | -5.61*** |
| γ4 | 0.2079 | 7.39*** |
| γ5 | -0.1499 | -5.93*** |
| γ6 | 0.1066 | 3.84*** |
| γ7 | -0.0606 | -2.17** |
| γ8 | 0.0086 | 0.43 |
Persistence:
0.963
Half-life:
18 days
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