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CBOE S&P 500 Left Tail Volatility Index Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Friday, July 24th, 2026

1 Day

182.64%

increased by 7.10%

1 Week

189.37%

increased by 13.83%

1 Month

199.07%

increased by 23.53%

Analysis last updated: Friday, July 24, 2026 at 11:30 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE S&P 500 Left Tail Volatility Index S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 2006 to Jul 17, 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 4 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.8530
4.33***
α

ARCH

Response to squared shocks

0.1992
7.72***
β

GARCH

Volatility persistence

0.6272
14.01***
γi Spline Coefficients
K=9
γ1-0.3292
-2.28**
γ20.4460
2.28**
γ3-0.3466
-2.84***
γ40.4849
4.19***
γ5-0.3790
-3.16***
γ60.2304
1.70*
γ7-0.1857
-1.44
γ80.1223
1.13
γ9-0.0613
-0.80

Persistence:

0.826

Half-life:

4 days