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V-Lab

CBOE VIX Indicative Bid Index Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Friday, August 21st, 2026

1 Day

121.63%

increased by 4.18%

1 Week

127.22%

increased by 9.77%

1 Month

134.62%

increased by 17.17%

Analysis last updated: Friday, August 21, 2026 at 11:34 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE VIX Indicative Bid Index S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Sep 18, 2009 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 3 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.7389
5.54***
α

ARCH

Response to squared shocks

0.1434
5.43***
β

GARCH

Volatility persistence

0.6667
9.56***
γi Spline Coefficients
K=8
γ1-0.1611
-1.05
γ20.1854
0.81
γ3-0.0014
-0.01
γ4-0.0639
-0.40
γ50.0886
0.65
γ6-0.2108
-1.39
γ70.4117
2.91***
γ8-0.3636
-4.36***

Persistence:

0.810

Half-life:

3 days