Compute empirical VaR

In this exercise, you will practice estimating dynamic 5% daily VaRs with an empirical approach.

The difference between parametric VaR and empirical VaR is how the quantiles are estimated. The parametric approach estimates quantiles from an assumed distribution assumption, while the empirical approach estimates quantiles from an observed distribution of the standardized residuals.

You will use the same GARCH model as the previous exercise. The mean and variance forecasts are saved in mean_forecast and variance_forecast respectively. The empirical standardized residuals have also been calculated and saved in std_resid.

This exercise is part of the course

GARCH Models in Python

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Exercise instructions

Compute 0.05 quantile from the GARCH standardized residuals std_resid.
Calculate VaR using mean_forecast, variance_forecast from the GARCH model and the quantile from the previous step.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

# Obtain the empirical quantile
q_empirical = ____.____(____)
print('5% empirical quantile: ', q_empirical)

# Calculate the VaR
VaR_empirical = ____.values + np.sqrt(____).values * ____
# Save VaR in a DataFrame
VaR_empirical = pd.DataFrame(VaR_empirical, columns = ['5%'], index = variance_forecast.index)

# Plot the VaRs
plt.plot(VaR_empirical, color = 'brown', label = '5% Empirical VaR')
plt.plot(VaR_parametric, color = 'red', label = '5% Parametric VaR')
plt.scatter(variance_forecast.index,bitcoin_data.Return['2019-1-1':], color = 'orange', label = 'Bitcoin Daily Returns' )
plt.legend(loc = 'upper right')
plt.show()

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