Last week, The Wall Street Journal reported that the US Securities and Exchange Commission had launched an inquiry into the relationship between trading platforms and high-speed firms, focusing on the practice of co-location.

The phenomenon, whereby a trading firm rents server space next to the exchange's matching engine, has emerged during the past five years as one of the central mechanisms behind high-speed trading: by locating its server right next to the exchange, the trading firm receives data feeds much faster than firms located elsewhere giving it an information advantage on which it can trade.