Skip to main content
V-Lab
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

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Schwab Short-Term U.S. Treasury ETF GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Aug 5, 2010 to Sep 11, 2026

Model 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
ParamValuet-stat
ωconst0.0063
1.97**
αARCH0.0554
13.10***
βGARCH0.9979
1,082.31***
νDF6.7893
2.83***

0.998

Persistence

328d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-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