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V-Lab

S&P 1000 Index Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Wednesday, August 19th, 2026

1 Day

15.08%

increased by 1.86%

1 Week

15.40%

increased by 2.18%

1 Month

16.46%

increased by 3.24%

Analysis last updated: Tuesday, August 18, 2026 at 11:06 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P 1000 Index S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Dec 29, 1994 to Aug 14, 2026

Model Insight

This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 39 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.7869
8.99***
α

ARCH

Response to squared shocks

0.1065
10.43***
β

GARCH

Volatility persistence

0.8759
84.36***
γi Spline Coefficients
K=1
γ1-0.0005
-2.90***

Persistence:

0.982

Half-life:

39 days