Book excerpt: This Element is an excerpt from Crapshoot Investing: How Tech Savvy Traders and Clueless Regulators Turned the Stock Market into a Casino (9780132599689) by Jim McTague. Available in print and digital formats. How the nerds took over Wall Street–and how their high-frequency, computer-driven trading impacts your portfolio. How did graduates from physics and math departments of top graduate schools end up swarming Wall Street? It was an unanticipated consequence of new SEC regulations intended to encourage electronic exchanges. The sudden fragmentation of the market resulted in unexpected complexity which, in turn, led to fleeting pricing discrepancies among trading venues. The nerds saw ways to exploit these inefficiencies.