We use quasi-exogenous variation in trading activity at the sub-second frequency to show that higher trade and quote intensities cause higher volatility but perhaps surprisingly have no significant effect on stock liquidity. This result has significant implications for the theories of strategic...

This paper documents a stark periodicity in intraday volume and in the number of trades. We find activity in both variables spikes by about 20% at regular intervals of 5 or 10 minutes throughout the trading day. We argue that this activity is the result of algorithmic trading influenced by human...

A unique data set from NASDAQ OMX Nordic allows a deep analysis of trader types' activity and provides evidence on the roles played in the trading ecosystem. We specifically investigate the impact of algorithmic traders on market quality relative to the activities of other market participants...