V-Lab
Schwab Short-Term U.S. Treasury ETF GAS-GARCH Student T Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
1.30%
decreased by 0.04%
1 Week
1.30%
decreased by 0.04%
1 Month
1.30%
decreased by 0.04%
Analysis last updated: Friday, September 11, 2026 at 11:50 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Aug 5, 2010 to Sep 11, 2026Model Insight
With persistence 0.998, volatility shocks have a half-life of 328 trading days (~1.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 6.79 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
Tap to view equation
High persistence: persistence 0.998, shock half-life ~328 daysv = 6.79 · fat tails
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0063 | 1.97** |
| αARCH | 0.0554 | 13.10*** |
| βGARCH | 0.9979 | 1,082.31*** |
| νDF | 6.7893 | 2.83*** |
0.998
Persistence328d
Half-life𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0063 | 1.97** |
α ARCH Response to squared shocks | 0.0554 | 13.10*** |
β GARCH Volatility persistence | 0.9979 | 1,082.31*** |
ν DF Student-t tail thickness | 6.7893 | 2.83*** |
Persistence:
0.998
Half-life:
328 days
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