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V-Lab
V-Lab

Russell 1000 Growth Index Spline-GARCH Volatility Analysis

Volatility prediction for Friday, September 11th, 2026

1 Day

16.93%

increased by 0.18%

1 Week

17.47%

increased by 0.72%

1 Month

19.26%

increased by 2.51%

Analysis last updated: Friday, September 11, 2026 at 09:04 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Russell 1000 Growth Index SGARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

May 12, 2000 to Sep 4, 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 38 trading days.

τ

Spline-GARCH Model

Tap to view equation

Time-varying baseline: volatility reverts to a slowly-shifting spline trend
ParamValuet-stat
ωconst1.2885
7.22***
αARCH0.1060
10.45***
βGARCH0.8758
81.25***
γi Spline Coefficients
K=1
γ10.0047
3.53***

0.982

Persistence

38d

Half-life
τ

Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

1.2885
7.22***
α

ARCH

Response to squared shocks

0.1060
10.45***
β

GARCH

Volatility persistence

0.8758
81.25***
γi Spline Coefficients
K=1
γ10.0047
3.53***

Persistence:

0.982

Half-life:

38 days