Chordia, Roll and Subrahmanyam (2005, CRS) estimate the speed of convergence to market efficiency based on short-horizon return predictability of the 150 largest NYSE firms. We extend CRS to a broad panel of NYSE stocks and are the first to examine the relation between electronic communication...

On 23 April 1997, the Toronto Stock Exchange closed its trading floor, making it at that time the second-largest stock exchange in North America to choose a purely electronic trading environment for its equities. Exploiting this natural experiment, we find that the move to electronic trading...