V-Lab
S&P GSCI Agricultural Spot Index GJR-GARCH Volatility Analysis
Volatility prediction for Monday, August 31st, 2026
1 Day
19.97%
increased by 0.05%
1 Week
19.93%
increased by 0.01%
1 Month
19.80%
decreased by 0.12%
Analysis last updated: Friday, August 28, 2026 at 11:10 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Aug 28, 2026Model Insight
With persistence 0.991, volatility shocks have a half-life of 75 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0117 | 4.77*** |
α ARCH Response to squared shocks | 0.0626 | 6.13*** |
β GARCH Volatility persistence | 0.9352 | 156.88*** |
γ leverage Additional response to negative shocks | -0.0138 | -0.83 |
Persistence:
0.991
Half-life:
75 days
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