High-frequency traders in financial markets have been making media headlines. As a relatively new phenomenon, much of the discussion is not backed by solid academic research. In this special issue of the Journal of Financial Markets on High-Frequency Trading, we present several research papers...

We examine the dynamic relation between return and volume of individual stocks. Using a simple model in which investors trade to share risk or speculate on private information, we show that returns generated by risk-sharing trades tend to reverse themselves while returns generated by speculative...