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V-Lab

Vanguard S&P 500 Index ETF GJR-GARCH Volatility Analysis

Volatility prediction for Monday, August 24th, 2026

1 Day

12.93%

decreased by 0.65%

1 Week

13.11%

decreased by 0.47%

1 Month

13.63%

increased by 0.05%

Analysis last updated: Saturday, August 22, 2026 at 01:41 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Vanguard S&P 500 Index ETF GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Nov 8, 2012 to Aug 21, 2026

Model Insight

Volatility shocks decay with a half-life of 13 trading days, meaning a shock loses half its impact after approximately 13 days.

σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0435
16.32***
α

ARCH

Response to squared shocks

0.0000
0.00
β

GARCH

Volatility persistence

0.8467
184.95***
γ

leverage

Additional response to negative shocks

0.2056
16.86***

Persistence:

0.950

Half-life:

13 days