V-Lab
S&P BSE SENSEX Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Tuesday, September 15th, 2026
1 Day
9.95%
decreased by 0.33%
1 Week
10.18%
decreased by 0.10%
1 Month
10.89%
increased by 0.61%
Analysis last updated: Friday, September 11, 2026 at 12:03 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
Zero Slope Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.1410 | 5.33*** |
| αARCH | 0.0907 | 8.92*** |
| βGARCH | 0.8790 | 72.08*** |
Spline Coefficients
K=9
| γ1 | -0.1363 | -2.80*** |
| γ2 | 0.2588 | 3.58*** |
| γ3 | -0.2518 | -5.17*** |
| γ4 | 0.2480 | 5.17*** |
| γ5 | -0.2002 | -4.43*** |
| γ6 | 0.1007 | 2.50** |
| γ7 | 0.0053 | 0.13 |
| γ8 | -0.0487 | -1.11 |
| γ9 | 0.0371 | 1.15 |
0.970
Persistence23d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.1410 | 5.33*** |
α ARCH Response to squared shocks | 0.0907 | 8.92*** |
β GARCH Volatility persistence | 0.8790 | 72.08*** |
Spline Coefficients
K=9
| γ1 | -0.1363 | -2.80*** |
| γ2 | 0.2588 | 3.58*** |
| γ3 | -0.2518 | -5.17*** |
| γ4 | 0.2480 | 5.17*** |
| γ5 | -0.2002 | -4.43*** |
| γ6 | 0.1007 | 2.50** |
| γ7 | 0.0053 | 0.13 |
| γ8 | -0.0487 | -1.11 |
| γ9 | 0.0371 | 1.15 |
Persistence:
0.970
Half-life:
23 days
Other S&P BSE SENSEX Index Analyses
Other Zero Slope Spline-GARCH Analyses on Equity Indices