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V-Lab

S&P 500 Index GJR-GARCH Volatility Analysis

Volatility prediction for Monday, September 14th, 2026

1 Day

11.00%

decreased by 0.32%

1 Week

11.28%

decreased by 0.04%

1 Month

12.20%

increased by 0.88%

Analysis last updated: Saturday, September 12, 2026 at 12:55 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P 500 Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 1, 1990 to Sep 11, 2026

Model Insight

This asset exhibits a strong leverage effect: volatility responds almost entirely to negative shocks. The ARCH response to positive shocks is negligible.

σ

GJR-GARCH Model

Tap to view equation

Leverage: volatility responds almost entirely to negative shocks
ParamValuet-stat
ωconst0.0216
5.16***
αARCH0.0035
0.36
βGARCH0.8972
104.20***
γleverage0.1602
7.43***

0.981

Persistence

36d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0216
5.16***
α

ARCH

Response to squared shocks

0.0035
0.36
β

GARCH

Volatility persistence

0.8972
104.20***
γ

leverage

Additional response to negative shocks

0.1602
7.43***

Persistence:

0.981

Half-life:

36 days