The book "Flash Boys" by Michael Lewis reveals a critical issue in the stock market, where the timing of order execution across different exchanges creates vulnerabilities for traders. Certain individuals exploit these discrepancies, allowing them to front-run orders, which means they can see a market order and place their own orders ahead of it for profit. This practice undermines the fairness and integrity of the trading system, giving those who manipulate the timing an unfair advantage over others.

This manipulation highlights the complexities of modern trading, where technology plays a significant role. As market orders are processed at varying speeds on different exchanges, those aware of these delays can act swiftly to capitalize on them, distorting market dynamics. The book sheds light on the need for regulation and transparency to protect investors from these predatory tactics and to promote a level playing field in financial markets.