A small group of financial firms are using their technological superiority to skim the top off the market, Michael Lewis claims in his new book "Flash Boys." There's an increasingly heated debate over whether the practices, known as high-frequency trading, are harmful or helpful. Lewis, for his part, says the market is "rigged," and several federal agencies, including the Department of Justice, are now looking intowhat Charles Schwab recently labeled "a growing cancer."
Sophisticated and expensive computers allow high-frequency traders to take advantage of minuscule differences in price among the many exchanges where securities are bought and sold. Some firms pay to place their computers on the site of a stock exchange to be sure their access to price data is as fast as possible, a practice known as colocation; others will use technology to obscure their trading intentions for a few crucial thousandths of a second. Lewis's book tells the story of Brad Katsuyama, a former trader at the Royal Bank of Canada in New York. Katsuyama opened a new stock exchange last year to give investors protection from HFT.