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CBOE S&P 500 9-Day Volatility Index GJR-GARCH Volatility Analysis

Volatility prediction for Friday, September 11th, 2026

1 Day

196.45%

increased by 2.97%

1 Week

195.80%

increased by 2.32%

1 Month

193.74%

increased by 0.26%

Analysis last updated: Friday, September 11, 2026 at 11:30 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE S&P 500 9-Day Volatility Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 2011 to Sep 4, 2026

Model Insight

Volatility shocks decay with a half-life of 19 trading days, meaning a shock loses half its impact after approximately 19 days.

σ

GJR-GARCH Model

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Shock decay: Shocks decay with a 19-day half-life
ParamValuet-stat
ωconst5.0000
2.03**
αARCH0.0569
2.93***
βGARCH0.9355
58.51***
γleverage-0.0569
-1.54

0.964

Persistence

19d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

5.0000
2.03**
α

ARCH

Response to squared shocks

0.0569
2.93***
β

GARCH

Volatility persistence

0.9355
58.51***
γ

leverage

Additional response to negative shocks

-0.0569
-1.54

Persistence:

0.964

Half-life:

19 days