V-Lab
S&P BSE SENSEX Index Spline-GARCH Volatility Analysis
Volatility prediction for Thursday, September 17th, 2026
1 Day
10.29%
decreased by 0.20%
1 Week
10.41%
decreased by 0.08%
1 Month
10.81%
increased by 0.32%
Analysis last updated: Wednesday, September 16, 2026 at 01:09 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Sep 11, 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 23 trading days.
τ
Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.1641 | 5.42*** |
| αARCH | 0.0914 | 9.02*** |
| βGARCH | 0.8790 | 72.84*** |
Spline Coefficients
K=9
| γ1 | -0.1430 | -2.97*** |
| γ2 | 0.2741 | 3.81*** |
| γ3 | -0.2694 | -5.53*** |
| γ4 | 0.2656 | 5.50*** |
| γ5 | -0.2154 | -4.70*** |
| γ6 | 0.1119 | 2.72*** |
| γ7 | -0.0042 | -0.10 |
| γ8 | -0.0351 | -0.66 |
| γ9 | 0.0071 | 0.11 |
0.970
Persistence23d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.1641 | 5.42*** |
α ARCH Response to squared shocks | 0.0914 | 9.02*** |
β GARCH Volatility persistence | 0.8790 | 72.84*** |
Spline Coefficients
K=9
| γ1 | -0.1430 | -2.97*** |
| γ2 | 0.2741 | 3.81*** |
| γ3 | -0.2694 | -5.53*** |
| γ4 | 0.2656 | 5.50*** |
| γ5 | -0.2154 | -4.70*** |
| γ6 | 0.1119 | 2.72*** |
| γ7 | -0.0042 | -0.10 |
| γ8 | -0.0351 | -0.66 |
| γ9 | 0.0071 | 0.11 |
Persistence:
0.970
Half-life:
23 days
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