V-Lab
HSI Volatility Index Spline-GARCH Volatility Analysis
Volatility prediction for Friday, September 25th, 2026
1 Day
32.67%
decreased by 1.42%
1 Week
32.39%
decreased by 1.70%
1 Month
31.73%
decreased by 2.36%
Analysis last updated: Friday, September 25, 2026 at 09:00 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jul 16, 2010 to Sep 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 8 trading days.
τ
Spline-GARCH Model
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Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.6421 | 5.59*** |
| αARCH | 0.1008 | 5.63*** |
| βGARCH | 0.8122 | 23.02*** |
Spline Coefficients
K=9
| γ1 | -0.9784 | -3.12*** |
| γ2 | 1.5715 | 3.13*** |
| γ3 | -0.9628 | -2.62*** |
| γ4 | 0.5958 | 1.98** |
| γ5 | -0.3656 | -1.32 |
| γ6 | 0.2230 | 0.78 |
| γ7 | -0.3404 | -1.15 |
| γ8 | 0.8830 | 2.55** |
| γ9 | -2.0120 | -2.32** |
0.913
Persistence8d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.6421 | 5.59*** |
α ARCH Response to squared shocks | 0.1008 | 5.63*** |
β GARCH Volatility persistence | 0.8122 | 23.02*** |
Spline Coefficients
K=9
| γ1 | -0.9784 | -3.12*** |
| γ2 | 1.5715 | 3.13*** |
| γ3 | -0.9628 | -2.62*** |
| γ4 | 0.5958 | 1.98** |
| γ5 | -0.3656 | -1.32 |
| γ6 | 0.2230 | 0.78 |
| γ7 | -0.3404 | -1.15 |
| γ8 | 0.8830 | 2.55** |
| γ9 | -2.0120 | -2.32** |
Persistence:
0.913
Half-life:
8 days
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