This paper investigates whether positive and negative returns share the same dynamic volatility process. The well established stylized facts on volatility persistence and asymmetric effects are re-examined in light of such dichotomy. To analyze the dynamics of up and down volatilities estimated...

The bootstrap of test statistics requires the re-estimation of the model's parameters for each bootstrap sample. When parameter estimates are not available in closed form, this procedure becomes computationally demanding as each replication requires the numerical optimization of an objective...