Philip Delves Broughton, NYT, Flash Boys for the People, here. So, HFT is a Schwab Cancer that consumes Canadian retail commissions before they can be processed by the Schwab host? I can see why they might be upset.
These advantages were demonstrated in a recent natural experiment set off by Canada’s stock market regulators. In April 2012 they limited the activity of high-frequency traders by increasing the fees on market messages sent by all broker-dealers, such as trades, order submissions and cancellations. This affected high-frequency traders the most, since they issue many more messages than other traders.
The effect, as measured by a group of Canadian academics, was swift and startling. The number of messages sent to the Toronto Stock Exchange dropped by 30 percent, and the bid-ask spread rose by 9 percent, an indicator of lower liquidity and higher transaction costs.