Prices of the highly liquid S&P500 exchange traded fund (SPY) and the E-mini future (ES) respond to macroeconomic announcement surprises within five milliseconds, with trading intensity increasing over a hundred-fold following the news release. However, profits from trading quickly are...

In theoretical models, liquidity and order flow volatility are determined by the same exogenous parameters. Thus, the variability of order flow can at least partially proxy for the unobserved (true) liquidity. Levels of and shocks to order flow volatility are indeed positively and significantly...

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...