This study investigates empirically the presence of nonlinearities in the Athens Composite Share Price Index high-frequency returns. A preliminary analysis indicates that volatility exhibits a periodic intraday inverse J-shaped pattern, associated with the opening and closing of the market....

High frequency trading (HFT) depends on sophisticated algorithms to closely monitor price changes across securities. Theory predicts this technological advantage should translate into market-wide liquidity co-variation, by transmitting information-based liquidity shocks. Using a dataset of...