Skip to main content
V-Lab
V-Lab

S&P 500 Index Asy. Power MEM Volatility Analysis

Volatility prediction for Wednesday, October 7th, 2026

1 Day

9.87%

decreased by 0.91%

1 Week

9.84%

decreased by 0.94%

1 Month

9.73%

decreased by 1.05%

Analysis last updated: Wednesday, October 7, 2026 at 12:03 AM UTC

Press Delete or Backspace to remove this series.
Date Range:

from

10/06/2024

to

10/06/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P 500 Index APMEM

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 1, 1990 to Oct 2, 2026

Model Insight

This asset exhibits a strong leverage effect: negative returns increase next-day volatility 101% more than equivalent positive returns. The volatility power δ = 1.04 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.

μ

APMEM Model

Tap to view equation

Leverage: Negative returns increase volatility 101% more than positive returnsδ = 1.04 · sub-quadratic power
ParamValuet-stat
ωconst0.0327
9.80***
αARCH0.1890
14.63***
βGARCH0.7928
60.90***
γleverage0.3227
8.22***
δpower1.0392
8.72***

0.944

Persistence

12d

Half-life
μ

APMEM Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0327
9.80***
α

ARCH

Response to squared shocks

0.1890
14.63***
β

GARCH

Volatility persistence

0.7928
60.90***
γ

leverage

Additional response to negative shocks

0.3227
8.22***
δ

power

Transformation power

1.0392
8.72***

Persistence:

0.944

Half-life:

12 days