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V-Lab

State Street SPDR S&P Biotech ETF GJR-GARCH Volatility Analysis

Volatility prediction for Monday, September 21st, 2026

1 Day

27.61%

decreased by 0.37%

1 Week

27.75%

decreased by 0.23%

1 Month

28.22%

increased by 0.24%

Analysis last updated: Friday, September 18, 2026 at 11:22 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of State Street SPDR S&P Biotech ETF GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Feb 6, 2006 to Sep 18, 2026

Model Insight

This asset exhibits a strong leverage effect: volatility responds almost entirely to negative shocks. The ARCH response to positive shocks is negligible.

σ

GJR-GARCH Model

Tap to view equation

Leverage: volatility responds almost entirely to negative shocks
ParamValuet-stat
ωconst0.0762
3.95***
αARCH0.0161
1.83*
βGARCH0.9140
89.66***
γleverage0.0995
3.96***

0.980

Persistence

34d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0762
3.95***
α

ARCH

Response to squared shocks

0.0161
1.83*
β

GARCH

Volatility persistence

0.9140
89.66***
γ

leverage

Additional response to negative shocks

0.0995
3.96***

Persistence:

0.980

Half-life:

34 days