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CBOE S&P 500 Left Tail Volatility Index GJR-GARCH Volatility Analysis

Volatility prediction for Friday, September 11th, 2026

1 Day

159.34%

increased by 6.72%

1 Week

164.37%

increased by 11.75%

1 Month

181.22%

increased by 28.60%

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 Left Tail Volatility Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 2006 to Sep 4, 2026

Model Insight

Volatility shocks decay with a half-life of 40 trading days, meaning a shock loses half its impact after approximately 40 days.

σ

GJR-GARCH Model

Tap to view equation

Shock decay: Shocks decay with a 40-day half-life
ParamValuet-stat
ωconst5.0000
3.71***
αARCH0.0973
3.15***
βGARCH0.8796
56.44***
γleverage0.0121
0.18

0.983

Persistence

40d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

5.0000
3.71***
α

ARCH

Response to squared shocks

0.0973
3.15***
β

GARCH

Volatility persistence

0.8796
56.44***
γ

leverage

Additional response to negative shocks

0.0121
0.18

Persistence:

0.983

Half-life:

40 days