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V-Lab

NASDAQ Composite Index Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Thursday, August 20th, 2026

1 Day

18.51%

decreased by 0.86%

1 Week

18.81%

decreased by 0.56%

1 Month

19.72%

increased by 0.35%

Analysis last updated: Thursday, August 20, 2026 at 12:03 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of NASDAQ Composite Index S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 1, 1990 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 18 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.7506
7.35***
α

ARCH

Response to squared shocks

0.0998
10.31***
β

GARCH

Volatility persistence

0.8633
71.90***
γi Spline Coefficients
K=8
γ10.0095
0.33
γ20.0479
1.07
γ3-0.1730
-5.52***
γ40.2052
7.27***
γ5-0.1481
-5.86***
γ60.1058
3.81***
γ7-0.0608
-2.18**
γ80.0093
0.46

Persistence:

0.963

Half-life:

18 days