V-Lab
Russell 1000 Growth Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Monday, July 27th, 2026
1 Day
24.57%
increased by 0.37%
1 Week
24.59%
increased by 0.39%
1 Month
24.66%
increased by 0.46%
Analysis last updated: Saturday, July 25, 2026 at 12:05 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
May 12, 2000 to Jul 24, 2026Model Insight
With persistence 0.995, volatility shocks have a half-life of 126 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 = 8.36 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 | 2.7328 | 4.37*** |
α ARCH Response to squared shocks | 0.0952 | 39.45*** |
β GARCH Volatility persistence | 0.9945 | 777.59*** |
ν DF Student-t tail thickness | 8.3621 | 6.60*** |
Persistence:
0.995
Half-life:
126 days
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