V-Lab
HSI Volatility Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, July 24th, 2026
1 Day
68.49%
increased by 0.76%
1 Week
71.83%
increased by 4.10%
1 Month
81.20%
increased by 13.47%
Analysis last updated: Friday, July 24, 2026 at 11:21 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jul 16, 2010 to Nov 19, 2021Model 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 16 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.9573 | 7.00*** |
α ARCH Response to squared shocks | 0.0927 | 4.83*** |
β GARCH Volatility persistence | 0.8657 | 30.90*** |
Spline Coefficients
K=1
| γ1 | -0.0012 | -0.55 |
Persistence:
0.958
Half-life:
16 days
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