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V-Lab
V-Lab

S&P 100 Index MEM Volatility Analysis

Volatility prediction for Wednesday, September 16th, 2026

1 Day

9.50%

decreased by 0.18%

1 Week

9.91%

increased by 0.23%

1 Month

11.30%

increased by 1.62%

Analysis last updated: Tuesday, September 15, 2026 at 11:10 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P 100 Index MEM

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 50 trading days, meaning a shock loses half its impact after approximately 50 days.

μ

MEM Model

Tap to view equation

Shock decay: Shocks decay with a 50-day half-life
ParamValuet-stat
ωconst0.0212
2.86***
αARCH0.2213
14.31***
βGARCH0.7649
70.42***

0.986

Persistence

50d

Half-life
μ

MEM Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0212
2.86***
α

ARCH

Response to squared shocks

0.2213
14.31***
β

GARCH

Volatility persistence

0.7649
70.42***

Persistence:

0.986

Half-life:

50 days