V-Lab
State Street Technology Select Sector SPDR ETF GAS-GARCH Student T Volatility Analysis
Volatility prediction for Friday, July 31st, 2026
1 Day
38.36%
increased by 6.71%
1 Week
38.28%
increased by 6.63%
1 Month
37.97%
increased by 6.32%
Analysis last updated: Thursday, July 30, 2026 at 09:48 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 22, 1998 to Jul 24, 2026Model Insight
With persistence 0.995, volatility shocks have a half-life of 133 trading days (~0.5 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 8.76 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 3.4711 | 5.63*** |
α ARCH Response to squared shocks | 0.0867 | 47.40*** |
β GARCH Volatility persistence | 0.9948 | 1,018.23*** |
ν DF Student-t tail thickness | 8.7556 | 7.29*** |
Persistence:
0.995
Half-life:
133 days
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