V-Lab
Philippines Stock Exchange PSEi Index Spline-GARCH Volatility Analysis
Volatility prediction for Friday, September 18th, 2026
1 Day
17.22%
decreased by 0.39%
1 Week
17.80%
increased by 0.19%
1 Month
19.29%
increased by 1.68%
Analysis last updated: Friday, September 18, 2026 at 09:56 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Sep 17, 2026Model Insight
This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 11 trading days.
τ
Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.4443 | 8.12*** |
| αARCH | 0.1261 | 8.85*** |
| βGARCH | 0.8141 | 51.95*** |
Spline Coefficients
K=9
| γ1 | -0.0393 | -1.24 |
| γ2 | 0.1344 | 2.12** |
| γ3 | -0.2055 | -2.86*** |
| γ4 | 0.2019 | 3.38*** |
| γ5 | -0.1630 | -4.21*** |
| γ6 | 0.1077 | 3.02*** |
| γ7 | -0.0209 | -0.49 |
| γ8 | -0.0449 | -0.93 |
| γ9 | 0.0619 | 1.03 |
0.940
Persistence11d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.4443 | 8.12*** |
α ARCH Response to squared shocks | 0.1261 | 8.85*** |
β GARCH Volatility persistence | 0.8141 | 51.95*** |
Spline Coefficients
K=9
| γ1 | -0.0393 | -1.24 |
| γ2 | 0.1344 | 2.12** |
| γ3 | -0.2055 | -2.86*** |
| γ4 | 0.2019 | 3.38*** |
| γ5 | -0.1630 | -4.21*** |
| γ6 | 0.1077 | 3.02*** |
| γ7 | -0.0209 | -0.49 |
| γ8 | -0.0449 | -0.93 |
| γ9 | 0.0619 | 1.03 |
Persistence:
0.940
Half-life:
11 days
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