Dark pools emerged as a controversial feature of modern finance, representing private stock exchanges managed by major brokerage firms. These platforms operated away from the public eye, leading to concerns about transparency in trading. Although they did report trades afterward, the delay meant that market participants could not fully gauge the real-time activities within these dark pools, undermining the overall visibility of market dynamics.

The existence of dark pools highlights a significant shift in the financial marketplace, where information asymmetry became more pronounced. By keeping trading details confidential for a time, these exchanges contributed to the increasing complexity and opacity of market operations, leading to questions about fairness and the integrity of price-setting processes in the stock market.