For many Americans, the explosive phenomenon of online day trading didn't fully register until last August, when Mark O. Barton went on a shooting spree at two suburban Atlanta brokerage firms, where he had reportedly lost over $100,000 in investments. Not a pleasant introduction, to be sure, but not exactly inapt for a practice plagued by alarming suicide rates or, for the vast majority, the probability of quick financial ruin. As the first of what promises to be many books on the subject, Gregory Millman's informative The Day Traders is a concise and well-structured piece of reportage, with clear ideas about how "extreme investing" works and where it might be heading. Though Millman never fails to point out that day trading is absurdly risky—roughly 90% of participants take losses, and even the best can expect a rocky six-month learning curve—he's also encouraged by its impact in democratizing the market. Now, thanks to advanced software and a rash of cheap training programs, any workaday chump with a modem and a modest amount of capital can match wits with the power brokers and their stable of Ivy League-educated economists. A good speculator relies on instinctive, rather than thoughtful, responses to the fluctuating prices and, most importantly, has the humility to admit to a bad trade and cut a potentially heavy loss. But day trading hews much closer to gambling than real investing, and the house expects to win. As a sign of things to come, Millman traces its origins back to the hit-and-run tactics pioneered by Jesse Livermore, who made and lost millions shorting stocks in the late '20s before (what else?) committing suicide. Despite the collusive efforts of government and big business to quell this new "gold rush," The Day Traders offers plenty of evidence that it will continue to expand in America and around the globe. Though cautious in his enthusiasm, Millman makes a convincing argument for a revolution led by former teachers, receptionists, insurance agents, and other persistent thorns in the sides of the market makers.