S&P GSCI Grains Spot Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Friday, July 17th, 2026
1 Day
22.17%
decreased by 0.48%
1 Week
22.14%
decreased by 0.51%
1 Month
22.03%
decreased by 0.62%
Analysis last updated: Thursday, July 16, 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 10, 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 | 1.7098 | 13.25*** |
α ARCH Response to squared shocks | 0.0534 | 34.90*** |
β GARCH Volatility persistence | 0.9888 | 1,232.96*** |
ν DF Student-t tail thickness | 9.7247 | 4.32*** |
Persistence:
0.989
Half-life:
62 days
Other GAS-GARCH Student T Analyses on Commodities