V-Lab
S&P GSCI Agricultural Spot Index GJR-GARCH Volatility Analysis
Volatility prediction for Tuesday, July 28th, 2026
1 Day
21.20%
increased by 0.53%
1 Week
21.14%
increased by 0.47%
1 Month
20.93%
increased by 0.26%
Analysis last updated: Monday, July 27, 2026 at 11:03 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Jul 24, 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.
Inverse leverage: Positive returns increase volatility 28% more than negative returns
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0117 | 19.08*** |
α ARCH Response to squared shocks | 0.0628 | 24.47*** |
β GARCH Volatility persistence | 0.9350 | 625.82*** |
γ leverage Additional response to negative shocks | -0.0138 | -3.32*** |
Persistence:
0.991
Half-life:
75 days
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