V-Lab
S&P GSCI Cocoa Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Tuesday, September 29th, 2026
1 Day
51.98%
decreased by 0.88%
1 Week
51.88%
decreased by 0.98%
1 Month
51.50%
decreased by 1.36%
Analysis last updated: Monday, September 28, 2026 at 11:09 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 25, 2026Model Insight
With persistence 0.997, volatility shocks have a half-life of 228 trading days (~0.9 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
High persistence: persistence 0.997, shock half-life ~228 days
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.0764 | 8.00*** |
| αARCH | 0.0320 | 7.34*** |
| βGARCH | 0.9649 | 201.36*** |
Spline Coefficients
K=1
| γ1 | 0.0001 | 0.38 |
0.997
Persistence228d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.0764 | 8.00*** |
α ARCH Response to squared shocks | 0.0320 | 7.34*** |
β GARCH Volatility persistence | 0.9649 | 201.36*** |
Spline Coefficients
K=1
| γ1 | 0.0001 | 0.38 |
Persistence:
0.997
Half-life:
228 days
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