S&P GSCI Soybeans Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
17.23%
increased by 1.54%
1 Week
17.34%
increased by 1.65%
1 Month
17.76%
increased by 2.07%
Analysis last updated: Monday, July 20, 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 Jul 17, 2026Model Insight
Volatility shocks decay with a half-life of 58 trading days, meaning a shock loses half its impact after approximately 58 days. Returns follow a Student-t distribution with v = 6.85 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 | 1.8553 | 8.30*** |
α ARCH Response to squared shocks | 0.0558 | 34.16*** |
β GARCH Volatility persistence | 0.9882 | 695.39*** |
ν DF Student-t tail thickness | 6.8531 | 5.89*** |
Persistence:
0.988
Half-life:
58 days
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