V-Lab
S&P GSCI Grains Spot Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Friday, August 7th, 2026
1 Day
21.49%
decreased by 0.73%
1 Week
21.47%
decreased by 0.75%
1 Month
21.41%
decreased by 0.81%
Analysis last updated: Thursday, August 6, 2026 at 11:04 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Jul 31, 2026Model Insight
Volatility shocks decay with a half-life of 62 trading days, meaning a shock loses half its impact after approximately 62 days. Returns follow a Student-t distribution with v = 9.72 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.7114 | 13.21*** |
α ARCH Response to squared shocks | 0.0533 | 34.88*** |
β GARCH Volatility persistence | 0.9889 | 1,234.55*** |
ν DF Student-t tail thickness | 9.7220 | 4.32*** |
Persistence:
0.989
Half-life:
62 days
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