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V-Lab
V-Lab

S&P 100 Index GARCH Volatility Analysis

Volatility prediction for Thursday, September 17th, 2026

1 Day

10.76%

decreased by 0.22%

1 Week

11.03%

increased by 0.05%

1 Month

11.96%

increased by 0.98%

Analysis last updated: Thursday, September 17, 2026 at 03:45 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P 100 Index 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

Volatility shocks decay with a half-life of 45 trading days, meaning a shock loses half its impact after approximately 45 days.

σ

GARCH Model

Tap to view equation

Shock decay: Shocks decay with a 45-day half-life
ParamValuet-stat
ωconst0.0190
5.25***
αARCH0.0997
10.86***
βGARCH0.8849
98.16***

0.985

Persistence

45d

Half-life
σ

GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0190
5.25***
α

ARCH

Response to squared shocks

0.0997
10.86***
β

GARCH

Volatility persistence

0.8849
98.16***

Persistence:

0.985

Half-life:

45 days