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V-Lab

S&P GSCI Coffee Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Monday, August 31st, 2026

1 Day

47.37%

decreased by 1.51%

1 Week

47.07%

decreased by 1.81%

1 Month

45.95%

decreased by 2.93%

Analysis last updated: Friday, August 28, 2026 at 11:10 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P GSCI Coffee Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Aug 28, 2026

Model Insight

Volatility shocks decay with a half-life of 47 trading days, meaning a shock loses half its impact after approximately 47 days. Returns follow a Student-t distribution with v = 6.04 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

4.9512
2.49**
α

ARCH

Response to squared shocks

0.0442
8.12***
β

GARCH

Volatility persistence

0.9854
163.88***
ν

DF

Student-t tail thickness

6.0352
1.50

Persistence:

0.985

Half-life:

47 days