V-Lab
iShares MSCI Japan ETF GAS-GARCH Student T Volatility Analysis
Volatility prediction for Monday, September 21st, 2026
1 Day
17.63%
increased by 0.05%
1 Week
17.77%
increased by 0.19%
1 Month
18.31%
increased by 0.73%
Analysis last updated: Friday, September 18, 2026 at 10:46 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Apr 1, 1996 to Sep 18, 2026Model Insight
With persistence 0.997, volatility shocks have a half-life of 217 trading days (~0.9 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 7.33 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
Tap to view equation
High persistence: persistence 0.997, shock half-life ~217 daysv = 7.33 · fat tails
| Param | Value | t-stat |
|---|---|---|
| ωconst | 4.3228 | 1.91* |
| αARCH | 0.0740 | 16.37*** |
| βGARCH | 0.9968 | 617.22*** |
| νDF | 7.3254 | 3.05*** |
0.997
Persistence217d
Half-life𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 4.3228 | 1.91* |
α ARCH Response to squared shocks | 0.0740 | 16.37*** |
β GARCH Volatility persistence | 0.9968 | 617.22*** |
ν DF Student-t tail thickness | 7.3254 | 3.05*** |
Persistence:
0.997
Half-life:
217 days
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